Science Faculty Physics Combined Science Revision Pack FOUNDATION Date Title completed 03/02/2020 Energy 10/02/2020 Electricity: circuits and symbols 17/02/2020 Exam practice 24/02/2020 Eletricity; in our homes 02/03/2020 Particle model of matter 09/03/2020 Exam practice 16/03/2020 Atomic Strcuture 23/03/2020 Forces; application 30/03/2020 Forces; motion 06/04/2020 Exam practice 13/04/2020 Exam practice 20/04/2020 Waves 27/04/2020 Electromagnetism 04/05/2020 Equations and maths 11/05/2020 Longer answer questions 18/05/2020 Paper 1 revision: 20/05/2020 25/05/2020 Exam practice 01/06/2020 Exam practice 08/06/2020 Paper 2 revision: 15/06/2020
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Science Faculty
Physics Combined Science Revision Pack
FOUNDATION
Date Title completed 03/02/2020 Energy 10/02/2020 Electricity: circuits and symbols 17/02/2020 Exam practice 24/02/2020 Eletricity; in our homes 02/03/2020 Particle model of matter 09/03/2020 Exam practice 16/03/2020 Atomic Strcuture 23/03/2020 Forces; application 30/03/2020 Forces; motion 06/04/2020 Exam practice 13/04/2020 Exam practice 20/04/2020 Waves 27/04/2020 Electromagnetism 04/05/2020 Equations and maths 11/05/2020 Longer answer questions 18/05/2020 Paper 1 revision: 20/05/2020 25/05/2020 Exam practice 01/06/2020 Exam practice 08/06/2020 Paper 2 revision: 15/06/2020
AQA Trilogy: Combined Science
What to expect?
For the exam you will sit 2 papers each 70 minutes long
The topics covered in Paper 1 are;
1. Energy
2. Electricity
3. Particle model of matter
4. Atomic structure
The topics covered in Paper 2 are;
5. Forces
6. Waves
7. Magnetism and electromagnetism
Your total score from Physics will be added to that of Biology and Chemistry and your final
grade a result of the combined.
Expect the paper to cover all information from the above as well as 30% maths, 15%
required practical. Paper 2 will cover some of the content from paper 1 in that you may still
be requried to use the equations from the first 4 topics.
Key tips for the exam
Answer every question
Use key scientific words
Be prepared 30% of the paper will be maths
Use a calculator to answer questions
Look at the units for hints
Write an equation and substitute in numbers
Physics 1: Energy
Energy
check foundation higher triple
A system is an object or group of objects.
There are changes in the way energy is stored when a system changes.
Students should be able to describe all the changes involved in the way energy is stored when a system changes, for common situations. For example: • an object projected upwards • a moving object hitting an obstacle • an object accelerated by a constant force • a vehicle slowing down • bringing water to a boil in an electric kettle.
Throughout this section on Energy students should be able to calculate the changes in energy involved when a system is changed by: • heating • work done by forces • work done when a current flows
use calculations to show how the overall energy in a system is redistributed when the system is changed.
Students should be able to calculate the amount of energy associated with a moving object, a stretched spring and an object raised above ground level.
Students should be able to recall and apply this equation. kinetic energy = 0.5 × mass × speed2
The amount of elastic potential energy stored in a stretched spring can be calculated using the equation: elastic potential energy = 0.5 × spring constant × extension2
The amount of gravitational potential energy gained by an object raised above ground level can be calculated using the equation: g . p . e . = mass × gravitational field strength × height
The amount of energy stored in or released from a system as its temperature changes can be calculated using the equation: change in thermal energy = mass × specific heat capacity × temperature change which is given on the Physics equation sheet.
The specific heat capacity of a substance is the amount of energy required to raise the temperature of one kilogram of the substance by one degree Celsius.
investigation to determine the specific heat capacity of one or more materials. The investigation will involve linking the decrease of one energy store (or work done) to the increase in temperature and subsequent increase in thermal energy stored.
Power is defined as the rate at which energy is transferred or the rate at which work is done.
Students should be able to recall and apply both equations. power = energy transferred/time power = work done/time
An energy transfer of 1 joule per second is equal to a power of 1 watt.
Students should be able to give examples that illustrate the definition of power eg comparing two electric motors that both lift the same weight through the same height but one does it faster than the other.
Energy can be transferred usefully, stored or dissipated, but cannot be created or destroyed.
Students should be able to describe with examples where there are energy transfers in a closed system, that there is no net change to the total energy.
Students should be able to describe, with examples, how in all system changes energy is dissipated, so that it is stored in less useful ways. This energy is often described as being ‘wasted’.
Students should be able to explain ways of reducing unwanted energy transfers, for
example through lubrication and the use of thermal insulation.
The higher the thermal conductivity of a material the higher the rate of energy transfer by conduction across the material.
Students should be able to describe how the rate of cooling of a building is affected by the thickness and thermal conductivity of its walls.
The energy efficiency for any energy transfer can be calculated using the equation: efficiency = useful out put energy transfer/total in put energy transfer Efficiency may also be calculated using the equation: efficiency = useful power output/total power input Students should be able to recall and apply both equations.
Students should be able to describe ways to increase the efficiency of an intended energy transfer.
The main energy resources available for use on Earth include: fossil fuels (coal, oil and gas), nuclear fuel, bio-fuel, wind, hydroelectricity, geothermal, the tides, the Sun and water waves.
A renewable energy resource is one that is being (or can be) replenished as it is used.
The uses of energy resources include: transport, electricity generation and heating.
describe the main energy sources available
distinguish between energy resources that are renewable and energy resources that are non-renewable
compare ways that different energy resources are used, the uses to include transport, electricity generation and heating
understand why some energy resources are more reliable than others
describe the environmental impact arising from the use of different energy resources
explain patterns and trends in the use of energy resources.
consider the environmental issues that may arise from the use of different energy resources
show that science has the ability to identify environmental issues arising from the use of energy resources but not always the power to deal with the issues because of political, social, ethical or economic considerations.
This Sankey diagram shows the energy used in a filament lamp. What percentage of energy is dissipated as heat energy? What does this tell you about the efficiency?
1.4 The weightlifter’s internal store of energy decreased when he lifted the bar.
The bar’s internal store of energy increased by a smaller amount.
2.0 Electricity in the UK is produced from a number of energy resources. Figure 1 below shows the proportion of each energy resource used. The labels have been removed from the pie chart.
Figure 1
Energy source:
Advantage:
Disadvantage:
Energy source:
Advantage:
Disadvantage:
Energy source:
Advantage:
Disadvantage:
Energy source:
Advantage:
Disadvantage:
2.1 Complete the table.
[2 marks]
Energy resource Percentage of UK
electricity production Segment label
Coal 23
Natural gas 30
Nuclear power 21
Oil 1
Renewable fuels 25 A
2.2 Over the next 10 years, many of the UK’s nuclear power stations are expected to close. Suggest how this may affect the future balance of sources of energy used for electricity production in the UK.
If we can no longer use Nuclear power then what would the alternative be? Look at the chart on the previous page to suggest and evaluate alternatives.
4.4 Another lightbulb has a power of 12 W. It has an efficiency of 80%. Calculate the amount of time taken in seconds for the bulb to transfer 300 J of energy into light energy.
READ and WATCH: https://revisionscience.com/gcse-revision/physics/energy-resources-transfer/specific-heat-capacity
5.1 You have been asked to find out the best material for insulating a hot water tank. You have three materials: aluminium foil, cotton wool and expanded polystyrene. Describe an experiment to compare the effectiveness of these materials.
Include in your description the way you would use your results to decide the most effective material.
This means that you will need to use one of the required practicals you have learned. This should give you a clue as to which you will need.
Revision Checklist – use this list to identify your areas of strength and weakness to focus your revision
Specification Statement Revised RAG Describe all the changes involved in the way energy is stored when a system changes, for common
situations
Calculate the changes in energy involved when a system is changed Calculate the amount of energy associated with a moving object, a stretched spring and an object raised
above ground level
Determine the specific heat capacity of one or more materials Give examples that illustrate the definition of power e.g. comparing two electric motors that both lift the
same weight through the same height but one does it faster than the other.
Describe with examples where there are energy transfers in a closed system, that there is no net change to the total energy
Describe, with examples, how in all system changes energy is dissipated, so that it is stored in less useful ways
Explain ways of reducing unwanted energy transfers, for example through lubrication and the use of thermal insulation
Describe how the rate of cooling of a building is affected by the thickness and thermal conductivity of its walls
(HT only) Describe ways to increase the efficiency of an intended energy transfer
Describe the main energy sources available
Consider the environmental issues that may arise from the use of different energy resources
Keywords - Use these words to produce a glossary of key terms for this chapter
The topic in pictures – these images are hyperlinked to useful parts of the BBC Bitesize website – use them to access
1. Write the equation used to calculate the kinetic energy of a moving object.
2. Write the equation used to calculate the amount of elastic potential energy stored in a stretched spring.
3. What is the unit for kinetic energy, gravitational potential energy and elastic potential energy?
4. Write the equation used to calculate the amount of gravitational potential energy gained by an object raised
above ground level.
5. What is the rate at which energy is transferred or work is done?
6. Write two equations to calculate power.
7. What is the unit for Power?
8. What can be transferred usefully, stored or dissipated, but cannot be created or destroyed?
9. Write the equation for calculating the energy efficiency of any energy transfer.
10. What are the three main forms of fossil fuels used as energy resources?
11. State the three principle uses of energy resources.
12. Name seven renewable energy resources available for use on Earth.
13. What is a renewable resource?
Gravitational field strength
Kinetic energy
Force
Thermal
Elastic potential
Energy transfer
Conduction
Convection
Radiation
Fossil fuel
Generator
Renewable
Non-renewable
Power
Work done
Grades 5
Complete: Calculations using equations and remember units!
1. An object moves 5m, the work done is 65J, calculate the force acting on the object.
2. A bus is travelling at 5m/s and has a mass of 500kg. Calculate the kinetic energy.
3. How fast is an object moving if it has 10,000J of kinetic energy and a mass of 5kg?
4. Calculate the GPE a 2kg object that is 10m above the ground (assume gravity is 10N).
5. A spring has a spring constant of 10N/m, the spring has 200J of EPE, calculate the extension of the spring?
6. What is the change in energy if an object with a specific heat capacity of 1200J/kg⁰C and mass of 15kg
increases in temperature by 20⁰C ?
7. What is the total energy transferred by a 200W device if it is on for 20seconds?
8. A light bulb takes in 30J of energy per second. It transfers 3J as useful light energy and 27J as heat energy.
Calculate the efficiency.
acting on the object. 2. A bus is travelling at 5m/s and has a mass of 500kg. Calculate the
kinetic energy. 3. How fast is an object moving if it has 10,000J of kinetic energy
and a mass of 5kg? 4. Calculate the GPE a 2kg object that is 10m above the ground
(assume gravity is 10N). 5. A spring has a spring constant of 10N/m, the spring has 200J of
EPE, calculate the extension of the spring? 6. What is the change in energy if an object with a specific heat
capacity of 1200J/kg⁰C and mass of 15kg increases in temperature by 20⁰C ?
7. What is the total energy transferred by a 200W device if it is on for 20seconds?
8. A light bulb takes in 30J of energy per second. It transfers 3J as useful light energy and 27J as heat energy. Calculate the efficiency.
Answers: 1. 2. 3. 4. 5. 6. 7. 8.
These questions and answers are fundamental to understanding this topic. Use these questions and answers to practice and revise from. Make que cards or simply cover the right hand side of the page and reveal each answer.
Question Answer R/A/G
1 What is the equation linking kinetic energy, mass and velocity?
Ek= 0.5mv2
2 What are the units of energy? joules
3 What are the units of mass? kilograms
4 What are the units of velocity? metres per second
5 What is the equation linking gravitational field strength, gravitational potential energy and height?
Ep=mgh
6 What are the units of gravitational field strength?
newtons per kilogram
7 What is the equation linking energy transferred, power and time?
P=E/t
8 What are the units of power? Watts
9 What is the definition of power? Power is the rate of transfer of energy or the rate of doing work
10 What is the equation linking power, time and work done?
P=W/t
11 What are the units of work done? Joules
12 What is the equation for calculating efficiency from energy?
Efficiency = useful energy output/total energy input
13 What is the equation for calculating efficiency from power?
Efficiency = useful power output/useful power input
14 What is the type of energy transferred when a force moves through a distance?
Mechanical transfer
15 Mechanical transfer is…? The energy transfer when a force moves through a distance
16 Electrical transfer is…? energy transferred when a charge moves?
17 What is the energy transferred when a charge moves?
electrical transfer
18 What is the energy transferred by electromagnetic radiation?
Radiation transfer
19 Radiation transfer is…? The energy transferred by electromagnetic radiation.
20 Heat transfer is…? Energy transferred when an object is heated.
21 When an object is heated the energy transfer is a…?
heat transfer
22 List the 4 energy transfer pathways. Mechanical, electrical, radiation and heat.
23 List 4 energy stores. Four from: chemical, kinetic, gravitational potential, elastic potential, internal, nuclear, magnetic, electrostatic.
24 Energy stored in objects which move. Kinetic
25 What is a kinetic energy store Energy stored in objects which move
26 Chemical energy is stored as…? chemicals waiting to react
27 A battery is a store of __________ energy. Chemical
28 Food is a store of __________ energy. Chemical
29 A moving object is a store of ____________ energy
Kinetic
30 What is a gravitational potential store? energy stored in objects raised up against the force of gravity.
31 A rock at the top of a hill is a store of gravitational potential
___________ energy.
32 What is an elastic potential store? Energy stored in an object which has been stretched or compressed.
33 A compressed spring is a store of ___________ energy
elastic potential
34 An inflated balloon is a store of __________ energy
elastic potential
35 The internal energy store is… energy stored in the movement of particles.
36 The internal energy store of an object can be changed by…?
heating or cooling
37 Energy stored in the nuclei of atoms is in the __________ store.
Nuclear
38 What is a nuclear energy store? Energy stored in the nuclei of atoms that can fuse or split.
39 What is the magnetic energy store? Energy stored in magnets that are attracting or repelling
40 What is the electrostatic energy store? Energy stored n electric charges that are attracting or repelling
41 Name two non-renewable energy resources Fossil fuels, nuclear fuel
42 What are some advantages of fossil fuels as an energy resource?
reliable, cheap
43 What is a reliable energy source one which can produce energy all the time.
44 What are some disadvantages of fossil fuels? carbon dioxide (greenhouse gas) produced leading to global warming. Can produce sulphur dioxide causing acid rain.
45 What are some advantages of nuclear fuel? No carbon dioxide produced, reliable.
46 What are some disadvantages of nuclear fuel?
nuclear waste remains radioactive for thousands of years. Expensive to build and decommission
47 List 4 renewable energy resources. Any 4 from: biofuel, wind, hydroelectricity, geothermal, tidal, wave, solar.
48 What are some advantages of biofuels? carbon neutral, reliable
49 What are some disadvantages of biofuels? production of fuel can damage ecosystems and reduce variety of crops grown
50 What are some advantages of wind power? No carbon dioxide produced
51 What are some disadvantages of wind power?
unreliable, expensive to construct
52 What are some advantages of hydroelectricity?
No carbon dioxide produced
53 What are some disadvantages of hydroelectricity?
blocks rivers preventing fish migration, unreliable (may not produce electricity during droughts)
54 What are some advantages of geothermal energy?
doesn't damage ecosystems, reliable.
55 What are some disadvantages of geothermal energy?
fluids drawn from ground may contain greenhouse gases such as CO2 and methane. These contribute to global warming
56 What are some advantages of tidal energy? No carbon dioxide produced.
57 What are some disadvantages of tidal energy?
unreliable - tides vary, may damage tidal ecosystem
58 What are some advantages of wave power? No carbon dioxide produced
59 What are some disadvantages of wave power?
unreliable - may not produce electricity when calm seas
60 What are some advantages of solar power? No carbon dioxide produced
61 What are some disadvantages of solar power?
unreliable - no electricity produced at night and limited on cloudy days. Expensive to construct.
62 What term is used to describe energy dissipation
becoming spread out or transferred to a "wasted" store?
63 What term is used to describe a method for reducing unwanted energy transfers by reducing friction?
lubrication
64 What is a thermal insulator? A non-conductive material which reduces thermal energy transfers.
65 What is the name for a method of reducing energy transfers by the use of non-conductive materials?
insulation
66 What is the law of conservation of energy? Energy cannot be created and destroyed but only transferred from one store to another.
67 Define specific heat capacity The energy needed to raise the temperature 1 kg of a material by 1ᵒC
Physics 2: Simple Circuits
Simple circuits check
foundation higher triple
circuit diagram symbols
Circuit diagrams use standard symbols for a switch, cell, battery, diode, resistor, variable resistor, LED, lamp, fuse, voltmeter, ammeter, thermistor, LDR
Electrical charge and
current
For electrical charge to flow through a closed circuit the circuit must include a source of potential difference.
Electric current is a flow of electrical charge. The size of the electric current is the rate of flow of electrical charge.
Students should be able to recall and apply charge flow = current × time equation.
A current has the same value at any point in a single closed loop.
Current, resistance
and potential difference
The current (I) through a component depends on both the resistance (R) of the component and the potential difference (V) across the component. The greater the resistance of the component the smaller the current for a given potential difference (pd) across the component.
Students should be able to recall and apply potential difference = current × resistance equation.
Required practical activity 3
Use circuit diagrams to set up and check appropriate circuits to investigate the factors affecting the resistance of electrical circuits. This should include: • the length of a wire at constant temperature • combinations of resistors in series and parallel.
Resistors
Students should be able to explain that, for some resistors, the value of R remains constant but that in others it can change as the current changes.
The current through an ohmic conductor (at a constant temperature) is directly proportional to the potential difference across the resistor. This means that the resistance remains constant as the current changes.
The resistance of components such as lamps, diodes, thermistors and LDRs is not constant; it changes with the current through the component.
The resistance of a filament lamp increases as the temperature of the filament increases.
The current through a diode flows in one direction only. The diode has a very high resistance in the reverse direction.
The resistance of a thermistor decreases as the temperature increases.
The applications of thermistors in circuits eg a thermostat is required.
The resistance of an LDR decreases as light intensity increases.
The application of LDRs in circuits eg switching lights on when it gets dark is required.
explain the design and use of a circuit to measure the resistance of a component by measuring the current through, and potential difference across, the component
draw an appropriate circuit diagram using correct circuit symbols.
Students should be able to use graphs to explore whether circuit elements are linear or non-linear and relate the curves produced to their function and properties.
Required practical activity 4
use circuit diagrams to construct appropriate circuits to investigate the I–V characteristics of a variety of circuit elements, including a filament lamp, a diode and a resistor at constant temperature.
Series and parallel circuits
There are two ways of joining electrical components, in series and in parallel. Some circuits include both series and parallel parts.
For components connected in series: • there is the same current through each component • the total potential difference of the power supply is shared between the components • the total resistance of two components is the sum of the resistance of each component.
For components connected in parallel: • the potential difference across each component is the same • the total current through the whole circuit is the sum of the currents through the separate components • the total resistance of two resistors is less than the resistance of the smallest individual resistor.
use circuit diagrams to construct and check series and parallel circuits that include a variety of common circuit components
describe the difference between series and parallel circuits
explain qualitatively why adding resistors in series increases the total resistance whilst adding resistors in parallel decreases the total resistance
explain the design and use of dc series circuits for measurement and testing purposes
calculate the currents, potential differences and resistances in dc series circuits
solve problems for circuits which include resistors in series using the concept of equivalent resistance.
Direct and alternating potential difference
Mains electricity is an ac supply. In the United Kingdom the domestic electricity supply has a frequency of 50 Hz and is about 230 V.
Students should be able to explain the difference between direct and alternating potential difference.
Most electrical appliances are connected to the mains using three core cable. The insulation covering each wire is colour coded for easy identification: live wire – brown, neutral wire – blue, earth wire – green and yellow stripes.
The live wire carries the alternating potential difference from the supply. The neutral wire completes the circuit. The earth wire is a safety wire to stop the appliance becoming live.
The potential difference between the live wire and earth (0 V) is about 230 V. The neutral wire is at, or close to, earth potential (0 V). The earth wire is at 0 V, it only carries a current if there is a fault.
Explain that a live wire may be dangerous even when a switch in the mains circuit is open
Explain the dangers of providing any connection between the live wire and earth.
Power
Students should be able to explain how the power transfer in any circuit device is related to the potential difference across it and the current through it, and to the energy changes over time
Students should be able to recall and apply both equations. power = potential difference × current power = current2 × resistance
Energy transfers in
everyday appliances
Everyday electrical appliances are designed to bring about energy transfers.
The amount of energy an appliance transfers depends on how long the appliance is switched on for and the power of the appliance.
Students should be able to describe how different domestic appliances transfer energy from batteries or ac mains to the kinetic energy of electric motors or the energy of heating devices.
Work is done when charge flows in a circuit.
Students should be able to recall and apply both equations. energy transferred = power × time energy transferred = charge flow × potential difference
explain how the power of a circuit device is related to the potential difference across it and the current through it
explain how the power of a circuit device is related to the energy transferred over a given time.
Students should be able to describe, with examples, the relationship between the power ratings for electrical appliances and the changes in stored energy when they are in use.
The National
Grid
The National Grid is a system of cables and transformers linking power stations to consumers.
Electrical power is transferred from power stations to consumers using the National Grid.
Step-up transformers are used to increase the potential difference from the power station to the transmission cables then step-down transformers are used to decrease, to a much lower value, the potential difference for domestic use.
Students should be able to explain why the National Grid system is an efficient way to transfer energy.
Revision Checklist – use this list to identify your areas of strength and weakness to focus your revision
Specification Statement Revised RAG Use circuit diagrams to set up and check appropriate circuits to investigate the factors affecting the
resistance of electrical circuits
Explain that, for some resistors, the value of R remains constant but that in others it can change as the current changes
Explain the design and use of a circuit to measure the resistance of a component by measuring the current through, and potential difference across, the component
Draw an appropriate circuit diagram using correct circuit symbols Use graphs to explore whether circuit elements are linear or non-linear and relate the curves produced to
their function and properties
Use circuit diagrams to construct appropriate circuits to investigate the I–V characteristics of a variety of circuit elements, including a filament lamp, a diode and a resistor at constant temperature
Describe the difference between series and parallel circuits
Calculate the currents, potential differences and resistances in dc series circuits
Explain the difference between direct and alternating potential difference
Explain that a live wire may be dangerous even when a switch in the mains circuit is open Explain how the power transfer in any circuit device is related to the potential difference across it and the
current through it, and to the energy changes over time
Describe how different domestic appliances transfer energy from batteries or ac mains to the kinetic energy of electric motors or the energy of heating devices
Describe, with examples, the relationship between the power ratings for domestic electrical appliances and the changes in stored energy when they are in use
Explain why the National Grid system is an efficient way to transfer energy
Keywords - Use these words to produce a glossary of key terms for this chapter
The topic in pictures – these images are hyperlinked to useful parts of the BBC Bitesize website – use them to access
4. In a series circuit, like in Diagram 1, how is the brightness of the first bulb affected when the second bulb is connected? Explain why this happens?
5. In a parallel circuit, like in Diagram 2, how is the brightness of the first bulb affected when the second bulb is connected? Explain why this happens?
9. Dan and Tom build a circuit like the one shown below.
(a) Name the component labelled X ........................................................
(b) What are Dan and Tom using the component labelled X to measure? ................................
(c) Dan says, “Ammeter 1 will show a lower reading than Ammeter 2 because the bulbs in the circuit use up the current.” Tom says, “Ammeter 1 will show the same reading as Ammeter 2 because current is not used up.”
Who is right? ..................................................
(d) If Ammeter 1 has a reading of 1.5A, what reading will Ammeter 2 show? ....................A
10. (a) The circuit above contains 2 cells. Describe what would happen to the bulbs if Dan and Tom added another cell.
2. 20,000 C of charge flows through a lamp in 1800 s?
3. 500,000 C of charge flows in 1 hour?
How much charge flows through a cell when...
4. A current of 1 A flows for 1 s?
5. A current of 3 A flows for 45 s?
6. A current of 5 A flows for 10 minutes?
How long does it take for...
7. A current of 3 A to transfer 90 C of charge?
8. A current of 1 A to transfer 90 C of charge?
9. A current of 5 A to transfer 1,000,000 C of charge?
Potential Difference Complete the following diagrams by filling in the missing values:
1. 2. 3.
4. 5. 6.
I = Q/t
2.5V
V
2.5V
2.5V
V
5V
V
3V 3V
V
3V
V
Current & Potential Difference Complete the following diagram by filling in the missing values:
Current, Potential Difference, & Resistance
What is the resistance of...
1. a fixed resistor with a potential difference of 5 V and a current of 0.1 A?
2. a thermistor with a potential difference of 10 V and a current of 0.5 A?
3. a LDR with a potential difference of 3 V and a current of 0.01 A?
How much current will be flowing when...
4. a potential difference of 2 V is applied across an LED with a resistance of 20 Ω?
5. a potential difference of 12 V is applied across a 500 Ω resistor?
6. a potential difference of 1.5 V is applied across an thermistor with a resistance of 30 Ω?
What potential difference is needed to make...
7. a current of 1 A to flow through a 1 Ω resistor?
8. a current of 3 A to flow through a 30 Ω resistor?
9. a current of 2 A to flow through a 40 Ω resistor?
Current, Potential Difference, & Power
What is the power rating of a bulb where...
1. The potential difference is 240 V and the current is 0.25 A?
2. The potential difference is 120 V and the current is 0.5 A?
3. The potential difference is 240 V and the current is 0.167 A?
How much current flows through the following appliances when connected to a 240 V mains power
supply?
4. A 2000 W kettle?
5. A 1.2 kW microwave?
6. A 400 W computer?
How much energy is transferred in each of the above when connected for...
7. 10 seconds?
8. 2 minutes?
9. 1 hour?
V = I x R
3V
V
0.2A
V
A1
V
V1
V
V2
V
V3
V
A2
V
P = I x V
E = P x t
Current
1. 100/20 = 5 A 2. 1800 s? 20,000/1800 = 11 A 3. 500,000/(1 x 60 x 60) = 138.9 ≈ 140 A 4. 1 x 1 = 1 C 5. 3 x 45 = 135 C 6. ? 5 x (10 x 60) = 3000 C 7. 90/3 = 30 s 8. 90/1 = 90 s 9. 1,000,000/5 = 200,000 s
A1 – 0.1 A A2 – 0.3 A V1 – 3 V V2 – 1.5 V V3 – 1.5 V
Current, Potential Difference, & Resistance
1. 5/0.1 = 50 Ω 2. 10/0.5 = 20 Ω 3. 3/0.01 = 300 Ω 4. 2/20 = 0.1 A 5. 12/500 = 0.024 A 6. 1.5/30 = 0.05 A 7. 1 x 1 = 1 V 8. 3 x 30 = 90 V 9. 2 x 40 = 80 V
Current, Potential Difference, & Power
1. 25 x 240 = 60 W 2. 0.5 x 120 = 60 W 3. 0.167 x 240 = 40 W
4. 2000/240 = 8.3 A 5. 2000/240 = 5 A 6. 400/240 = 1.7 A 7. Kettle: 2000 x 10 = 20,000 J Microwave: 1200
x 10 = 12,000 J Computer: 400 x 10 = 4,000 J 8. Kettle: 2000 x 120 = 240,000 J Microwave:
1200 x 120 = 144,000 J Computer: 400 x 120 = 48,000 J
9. Kettle: 2000 x 3600 = 7,200,000 J Microwave: 1200 x 4,320,000 = 12,000 J Computer: 400 x 3600 = 1,440,000 J
Grade 5
Series Circuits
In a series circuit, the components are connected in a _____________, between the ______________ and _________________ ends of the power supply, except for __________________ which are connected in parallel to the components. A break in any point in the circuit means that current cannot flow in a complete loop and the circuit will not work.
The current (A) is the ____________ throughout a series circuit
V = IR
The potential difference (voltage) in a series circuit is ________________ between the components. The total potential difference (voltage) is the sum of the potential difference (voltage) of the components.
Vtotal
= V1 + V
2 + V
3 + etc.
Itotal
= I1 = I
2 = I
3 = etc.
The resistance in a series circuit is the ______________ of all the resistances added together.
Rtotal
= R1 + R
2 + R
3 + etc.
By adding a resistor into the circuit, the two resistors must share the total p.d.. This means that the p.d. is lower. This makes the current lower as well. The bigger the resistor, the _____________ of the total p.d. it takes
Summary of series circuits
1. The pd of the cells adds up to the ____________ pd.
2. The source pd is _____________ across the components.
3. The current is the _____________ throughout the components
4. The total resistance of the circuit is the _________ of all the resistances of the separate components.
sum same source split
2V 2V 2V
2V + 2V + 2V = 6V
Reminder! The total potential difference across a circuit is the sum of the pds of the batteries. We refer to the sum total of the potential differences as the ‘source’ pd
Potential difference is the energy transferred to or from a coulomb (Q or C)
total
1
2
etc.
Parallel Circuits
In a parallel circuit the current ____________ into different branches and then recombines before it goes back into the supply. The total current flowing around the circuit is ____________ to the total of all the currents in all the branches. Remember that current is the flow of electrons. Each electron can only take one path.
V = p.d. (potential difference or voltage) I = current (amps or A) R = resistance (ohms or Ω)
V = IR
Components connected in parallel each have their own _____________ connected to the positive and negative terminals (except _____________, which are always connected in series). A break in the circuit will only affect that loop and not the others. _______________ will still flow to the loops that are connected.
In a parallel circuit the potential difference is the __________ for each component. Each coulomb of charge can only take _________ path. It ‘gives up’ its energy to the component in that pathway. This means that the ______________ _______________ is the same for each component in the circuit.
REMEMBER!! Potential difference is the energy transferred to or from a coulomb of charge (Q or C)
Vtotal
= V1 = V
2 = V
3 = etc.
In a parallel circuit, the total resistance is ________ than the resistance of the _____________ resistor (the component with least resistance). (Think back to the lunch queue analogy.) If __________ loops are added, there are more pathways for the current to take, which means that the resistance __________. Using V = IR, we know that an __________ in current means a ______________ in resistance.
1
𝑅𝑡𝑜𝑡𝑎𝑙=
1
𝑅1+
1
𝑅2+
1
𝑅3
+ 𝑒𝑡𝑐. You DO NOT need to remember this equation for the exam. Only that the total resistance is less than that of the smallest resistor.
These questions and answers are fundamental to understanding this topic. Use these questions and answers to practice and revise from. Make que cards or simply cover the right hand side of the page and reveal each answer.
Question Answer R/A/G
70 Draw the circuit symbol for a switch
71 Draw the circuit symbol for a closed switch
72 Draw the circuit symbol for a cell
73 Draw the circuit symbol for a battery
74 Draw the circuit symbol for a diode
75 Draw the circuit symbol for a resistor
76 Draw the circuit symbol for a variable resistor
77 Draw the circuit symbol for an LED
78 Draw the circuit symbol for a lamp
79 Draw the circuit symbol for a fuse
80 Draw the circuit symbol for a voltmeter
81 Draw the circuit symbol for an ammeter
82 Draw the circuit symbol for a thermistor
83 Draw the circuit symbol for an LDR
84 State the rule for current in a series circuit the current is the same at every point in the circuit and in every component
85 State the rule for potential difference in a series circuit
the total potential difference of the power supply is shared between components
86 State the rule for resistance in a series circuit
the more resistors, the greater the resistance. RT=R1+R2
87 State the rule for current in a parallel circuit
the total current through the whole circuit is the sum of the currents through the separate components
88 State the rule for potential difference in a parallel circuit
the potential difference across each branch in the circuit is the same
89 State the rule for resistance in a parallel circuit
adding more resistors in parallel decreases resistance
90 What colour is the live wire in a three core cable?
brown
91 What colour is the neutral wire in a three core cable?
blue
92 What colour is the earth wire in a three core cable?
green and yellow
93 The brown wire in a plug is the _______ live
94 The blue wire in a plug is the ________ neutral
95 The green and yellow wire in a plug is the ________
earth
96 The potential difference between the live wire and others in the plug is _____ V
230V
97 Current flows into an appliance through the _______ wire
live
98 Current flows out of an appliance through the ______ wire
neutral
99 The _________ wire is a safety feature of appliances
earth
100 Potential difference between the neutral wires and others in the plug should be ____ V
0V
101 Electric Current is….? the flow of electric charge
102 Potential difference between two points in a circuit is….?
the work done when a couloumb of charge passes between the points.
103 In a circuit the potential difference causes …..?
charge to flow
104 Resistance is…? caused by anything which opposes the flow of electric charge
105 Particles which can be 'charges' in electric circuits are…
electrons or ions
106 What is a series circuit? A circuit with only one route for charge to flow
107 What is a parallel circuit? A circuit with more than one route for charge to flow
108 State the equation which links charge flow, current and time
Q=It
109 State the equation which links current, potential difference and resistance
V=IR
110 State the equation which links current, potential difference and power
P=IV
111 State the equation which links current, power and resistance
P=I2R
112 State the equation which links energy transferred, power and time
E=Pt
113 State the equation which links charge flow, energy transferred and potential difference
E=QV
114 What is the unit of charge flow? Coulomb ( C )
115 What is the unit of current? Amps (A)
116 What is the unit for potential difference? Volts (V)
117 What is the unit for resistance? Ohms (Ω)
118 What is the unit for power? Watts (W)
119 Draw the I-V characteristic for a fixed resistor
120 Draw the I-V characteristic for a filament lamp see
121 Draw the I-V characteristic for a diode
122 Describe the I-V characteristic for a fixed resistor
Current and potential difference are directly proportional, resistance is constant
123 Describe the I-V characteristic of a filament lamp
Resistance is not constant, it increases as p.d. increases
124 Explain why resistance increases with increased p.d. in a filament lamp
temperature increases causing ions to vibrate and increasing collisions with electrons flowing through the filament
125 Describe the I-V characteristic of a diode The current only flows through the diode in one direction, there is a very high resistance in the reverse direction.
126 Current which regularly changes direction is called…
alternating current
127 An example of alternating current is…? mains electricity
128 Current which flows in one direction is…? direct current
129 An example of direct current is… batteries
130 What is the potential difference of mains electricity in the UK?
230V
131 What is the frequency of the alternating current in UK mains electricity?
50Hz
132 The national grid consists of…? Cables and transformers
133 Are power stations par of the national grid?
no
134 What does a step up transformer do? Increases p.d.
135 What does a step down transformer do? reduces p.d. to 230 V
136 Why are transformers used? reduce current so that less heat is lost in cables, increases efficiency
Science Faculty Physics 3: Particles Checklist
Particles
Density of materials
Students should be able to recall and apply the density equation to changes where mass is conserved. density = mass/volume
Students should be able to recognise/draw simple diagrams to model the difference between solids, liquids and gases.
Students should be able to explain the differences in density between the different states of matter in terms of the arrangement of atoms or molecules.
Required practical
activity 5:
Use appropriate apparatus to make and record the measurements needed to determine the densities of regular and irregular solid objects and liquids. Volume should be determined from the dimensions of regularly shaped objects, and by a displacement technique for irregularly shaped objects. Dimensions to be measured using appropriate apparatus such as a ruler, micrometer or Vernier callipers.
Changes of state
Students should be able to describe how, when substances change state (melt, freeze, boil, evaporate, condense or sublimate), mass is conserved.
Changes of state are physical changes which differ from chemical changes because the material recovers its original properties if the change is reversed.
Internal energy
Energy is stored inside a system by the particles (atoms and molecules) that make up the system. This is called internal energy.
Internal energy is the total kinetic energy and potential energy of all the particles (atoms and molecules) that make up a system.
Heating changes the energy stored within the system by increasing the energy of the particles that make up the system. This either raises the temperature of the system or produces a change of state.
Temperature changes in a system
If the temperature of the system increases, the increase in temperature depends on the mass of the substance heated, the type of material and the energy input to the system.
The specific heat capacity of a substance is the amount of energy required to raise the temperature of one kilogram of the substance by one degree Celsius.
Students should be able to apply Δ E m c Δ θ equation, which is given on the Physics equation sheet, to calculate the energy change involved when the temperature of a material changes.
Changes of heat and specific
latent heat
If a change of state happens: The energy needed for a substance to change state is called latent heat. When a change of state occurs, the energy supplied changes the energy stored (internal energy) but not the temperature.
The specific latent heat of a substance is the amount of energy required to change the state of one kilogram of the substance with no change in temperature.
Specific latent heat of fusion – change of state from solid to liquid/Specific latent heat of vaporisation – change of state from liquid to vapour
Students should be able to apply E = m L equation, which is given on the Physics equation sheet, to calculate the energy change involved in a change of state.
Students should be able to interpret heating and cooling graphs that include changes of state.
Students should be able to distinguish between specific heat capacity and specific latent heat.
Particle motion in
gases
The molecules of a gas are in constant random motion. The temperature of the gas is related to the average kinetic energy of the molecules.
Changing the temperature of a gas, held at constant volume, changes the pressure exerted by the gas.
explain how the motion of the molecules in a gas is related to both its temperature and its pressure
explain qualitatively the relation between the temperature of a gas and its pressure at constant volume.
Matter: Kinetic Molecular Model, and Thermal Properties In these notes: bullet points are from the Cambridge IGCSE syllabus. Text in italics is supplementary (extended).
1. Solids, Liquids and Gases: Properties and Particles
State the distinguishing properties of solids, liquids and gases.
Describe qualitatively the molecular structure of solids, liquids and gases.
Relate the properties of solids, liquids and gases to the forces and distances between molecules and to the motion of the molecules.
State Distinguishing Property Explanation in terms of particles
Solid (Atoms/molecules held very close together by strong attractions. They stay in their positions, but vibrate – move repeatedly backwards and forwards.)
The particles are strongly attracted and can’t change their positions.
The particles are very close together (and if you try to push them closer, they repel each other).
Liquid (Atoms/molecules are very close together but the attractions are weaker than in a solid. So they can move around, changing positions. Neighbouring particles may be temporarily attracted, but then break apart again.)
The particles are not strongly attracted, so they can move past each other.
Gravity pulls the liquid down, and the particles can’t escape from each other because they are attracted. But the attractions are not strong, so the particles move around and the liquid flows to fill the bottom of the container.
The particles are very close together (and if you try to push them closer, they repel each other).
Gas (Atoms/molecules are far apart, and there is no attraction between them. They move in random directions, at high speed.)
The particles are not attracted, so they do not stay together. (This is beyond IGCSE, but in case you’re wondering: gas particles can ‘defy’ gravity because they have a lot of energy for their size. Like a fast-moving rocket or a firework, they are energetic enough to overcome gravity.)
The particles are far apart, so they can be pushed closer together.
Not many particles per unit volume, so has a low mass per unit volume.
Warning! Students often think the particles are significantly farther apart in a liquid than in a solid. This is not true. If you draw the particles in a liquid, you should draw them touching.
The world ‘particles’ is used a lot below. It can mean either atoms, or molecules (two or more atoms bonded together). For example, a particle of iron is simply a single iron atom; whereas a particle of water is a molecule of H2O (two hydrogen atoms and one oxygen atom, bonded together), and a particle of sucrose is the molecule C12H22O11.
2. Heat and Temperature
Interpret the temperature of a gas in terms of the motion of its molecules. Firstly, heat and temperature are not the same thing (although they are related). Heat: a type of _____________. Heat can be transferred from one object or place to another, and we measure amounts of heat in ____________. When some heat enters an object, its temperature usually _______ (but not always – see later). Temperature: the temperature of an object is related to the average kinetic energy of its particles. The faster its particles are moving (either vibrating or moving around), the _________ its temperature. (Beyond IGCSE: the temperature of an object is directly proportional to the average kinetic energy of its particles.) Usually if you give an object some more heat, that extra energy is shared between the object’s particles. The average kinetic energy (and the speed) of the particles increases. This means it has a higher ________________ than before.
3. Thermal Expansion
Describe qualitatively the thermal expansion of solids, liquids and gases.
Identify and explain some of the everyday applications and consequences of thermal expansion.
Explain in terms of motion and arrangement of molecules the relative order of magnitude of the expansion of solids, liquids and gases.
Thermal expansion can be explained by the kinetic molecular model of matter. If the temperature of a substance rises, that means its particles are moving faster. This causes changes we can measure and sometimes actually see:
Solid Liquid Gas
The particles vibrate faster and farther. They push each other farther apart, so the solid expands a little.
The particles move around faster. They hit each other with more force, pushing each other farther apart. So the liquid expands a little.
The particles move around faster. They hit the insides of their container harder and more often. If the container is able to be pushed outwards by their increased force (e.g. a balloon, a syringe), then the gas will expand. Gases expand much more than solids and liquids.
Particles in a solid ___________ ___________________________ ___________________________; this stops them moving much farther apart, so the expansion in a solid is usually small.
Particles in a liquid ___________ ___________________________ ___________________________; this stops the liquid expanding as much as a gas, but allows it to expand more than a solid.
_____________________________ _____________________________ _____________________________ _____________________________, so gases expand a lot when their temperature rises.
Warning! Students often write that when a substance is heated, “its particles expand”. You would get no marks for this! The particles don’t expand – they stay the same size. The substance itself expands, because its particles move farther apart.
Thermal expansion - uses and risks: Applications Thermometers: The liquid (mercury, or more commonly alcohol) in a thermometer _____________ when heated, and can be used to show the temperature: Bimetallic strips: Different metals expand by different amounts when heated. If strips of two different metals are welded/stuck together, their different amounts of expansion causes them to bend. This phenomenon can be used for temperature measurement, or for cutting off a circuit when it gets too hot.
A bimetallic strip thermometer (left). This strip is bent into a spiral. When it expands, the spiral starts to open out, and the pointer moves round. Dealing with Risks When large structures like bridges expand in hot weather, this could cause serious danger and damage: the bridge could bend or crack. The pictures below show ‘expansion joints’ in bridges: they give room for the bridge to expand safely.
The same applies to railway tracks. On the left is a track which has got hot, expanded and buckled (notice the derailed train in the background). It is important to include small gaps in the rails so this doesn’t happen.
4. Evaporation Describe evaporation in terms of the escape of more energetic molecules from the surface of a liquid.
Relate evaporation to the consequent cooling.
Demonstrate understanding of how temperature, surface area and air flow over a surface influence evaporation.
Evaporation can be explained by the kinetic molecular model of matter (matter is made of moving particles). Evaporation is a change of state of a ____________ into a ____________ at a temperature ____________ the boiling point of the liquid. It happens at the liquid ____________, where some of the ____________ -moving particles escape. (In a liquid, there is an average particle speed, but some particles will be faster than this and some slower.) This lowers the average kinetic energy of the particles in the liquid – so the liquid’s ____________ drops.
Factors which increase the rate of evaporation:
speed of molecule (m/s)
no. of molecules at a particular speed
Average speed
5. Melting and Boiling Describe melting and boiling in terms of energy input without a change in temperature.
Distinguish between boiling and evaporation.
Describe condensation and solidification.
State the meaning of melting point and boiling point.
Use the terms latent heat of vaporisation and latent heat of fusion and give a molecular interpretation of
latent heat. Changes of State ‘States of matter’ are the physical states in which matter can exist: solid, liquid and gas. You need to remember the words we use for the changes between states:
Changes of state can be explained by the kinetic molecular model of matter: Melting happens when the particles of a solid get enough ____________ to partly break free of their attractions. This happens if the solid is given enough heat to reach its melting point (melting temperature), for example 0°C for ice. Boiling happens when the particles of a liquid get enough energy to break free of their ____________
completely. This happens if the liquid is given enough heat to reach its boiling point (boiling temperature), for example, 100°C for water. Water is an unusual substance. Most liquids contract (get smaller) as they get colder and then freeze. But when water gets close to freezing, its particles actually get farther apart. That’s because in solid water (ice), the particles fit together in a particular arrangement which is relatively spaced out (see diagrams). That means ice is less dense than water, which has some important consequences for our planet… Boiling and Evaporation
Evaporation Boiling
Involves liquid turning into gas. Involves liquid turning into gas.
Happens at any temperature (as long as the substance is a liquid).
Happens throughout the liquid. Bubbles appear and rise to the surface. These bubbles are filled with the gas version of the liquid. (E.g. when water boils, the bubbles are full of water in the gas state.)
Heat has to enter the liquid from outside to make boiling happen.
Slow.
SOLIDIFIES/FREEZES
Latent Heat When you boil a liquid, its temperature doesn’t go above the boiling point until it has finished boiling. For example, while you are boiling water, the temperature of the water stays at 100°C until all the water has boiled to water vapour.
This may seem strange: you are putting heat energy into the liquid, yet its temperature does not rise. Where is the energy going? The heat energy is used to break the intermolecular attractions between the molecules of the liquid; after the liquid has turned to gas, this energy is stored in the gas as potential energy. (The molecules now have the potential to come back together again to form a liquid. If they do, the stored chemical energy will turn back into heat energy.) The same thing happens when a solid melts. For example, if you heat ice so that it melts, the temperature of the ice+water mixture will stay at 0°C until all the ice has melted.
This diagram shows the energy and temperature changes when a substance melts or boils. (Ek means kinetic energy of the particles; Ep means potential energy of the particles.) Below is a heating curve for water; a heating curve is a graph showing the temperature of a substance plotted against the amount of energy it has absorbed. You may also see a cooling curve, which shows the temperature when a substance cools down.
6. Behaviour of Gases
Describe qualitatively the pressure of a gas in terms of the motion of its molecules.
Describe qualitatively the effect of a change of temperature on the pressure of a gas at constant volume.
Describe qualitatively the effect of a change of temperature on the volume of a gas at constant pressure.
Relate the change in volume of a gas to change in pressure applied to the gas at constant temperature and use the equation p V = constant at constant temperature.
Why do gases exert a pressure?
What happens to the pressure when you increase the temperature (but keep the volume the same – say, by trapping the gas inside a strong box)?
Cool gas Hot gas
What happens to the volume when you increase the temperature (but keep the pressure the same – say, by keeping the same weight on top of the gas)?
Lower temp. Higher temp.
If you keep the temperature of a gas the same but change its pressure, the volume will change. Or if you change the volume, the pressure will change:
In a gas at constant temperature, the pressure (p) is inversely proportional to the volume (V): that means if the pressure increases the volume decreases, and if the pressure decreases the volume increases. The relationship looks like this:
3 Particle model of matter – Trilogy
STUDY: Not only should you be able to draw the particle model but you need to be able to describe the structure and bonding too. https://www.bbc.co.uk/bitesize/guides/z3gxdxs/revision/1
1.0 A teacher uses a tray filled with table tennis balls to model how particles are arranged in materials, as shown in Figure 1.
Figure 1
1.1 Initially the balls are arranged in a regular pattern as shown in Figure 1.
Which state of matter is best represented by the balls in Figure 1?
[1 mark]
Tick one box.
solid
liquid
gas
1.2 The teacher then moves the tray from side to side so that the table tennis balls are no longer in a regular pattern.
Which state of matter is now best represented by the balls?
Revision Checklist – use this list to identify your areas of strength and weakness to focus your revision
Specification Statement Revised RAG
Recall and apply the density = mass/volume equation to changes where mass is conserved
Recognise/draw simple diagrams to model the difference between solids, liquids and gases Explain the differences in density between the different states of matter in terms of the arrangement of
atoms or molecules
Use appropriate apparatus to make and record the measurements needed to determine the densities of regular and irregular solid objects and liquids
Describe how, when substances change state (melt, freeze, boil, evaporate, condense or sublimate), mass is conserved
Apply the specific heat capacity equation, which is given on the Physics equation sheet, to calculate the energy change involved when the temperature of a material changes
Interpret heating and cooling graphs that include changes of state Apply the equation, which is given on the Physics equation sheet, to calculate the energy change involved
in a change of state
Distinguish between specific heat capacity and specific latent heat
Explain how the motion of the molecules in a gas is related to both its temperature and its pressure
Explain qualitatively the relation between the temperature of a gas and its pressure at constant volume
Keywords - Use these words to produce a glossary of key terms for this chapter
The topic in pictures – these images are hyperlinked to useful parts of the BBC Bitesize website – use them to access
2. True or False: changes of state are physical changes?
3. What is the total kinetic and potential energy of all particles that make up a system known as?
4. Which three factors affect the increase in temperature of a substance?
5. What is the amount of energy required to raise the temperature of a substance by 1oC known as?
6. What is the energy needed for one Kg of a substance to change state without a change in temperature
known as?
7. Describe the motion of molecules of a gas.
8. What happens to the pressure exerted by a gas, held at constant volume, when the temperature is
increased?
Keyword Definition
Solid
Liquid
Gas
Density
Internal energy
Specific heat capacity
Latent heat
Evaporate
Condense
Sublimate
Freeze
Melt
Boil
State of matter
Gas pressure
These questions and answers are fundamental to understanding this topic. Use these questions and answers to practice and revise from. Make que cards or simply cover the right hand side of the page and reveal each answer.
Question Answer R/A/G
137 How much mass a substance contains compared to it's volume is…
density
138 State the equation which links density, mass and volume
ρ m/v
139 Name the change of state when a liquid becomes a solid
freezing
140 Name the change of state when a solid becomes a liquid
melting
141 Name the change of state when a liquid becomes a gas
evaporation
142 Name the change of state when a gas becomes a liquid
condensation
143 Name the change of state when a solid becomes a gas (without passing through liquid form)
sublimation
144 Changes of state are caused by the amount of _________ a substance has
energy
145 State changes are examples of ___________ change
physical
146 Physical changes are ones which can be _____________
reversed
147 A change which creates new products and cannot be reversed is _________ change
chemical
148 The energy stored inside a system by the particles which make it up is known as ____________ energy
internal
149 What is internal energy? The total kinetic energy and potential energy of all the particles in a system
150 Energy stored within moving objects is __________
kinetic
151 Energy stored in particles because of their position is…?
potential energy
152 Particles wich are further apart have _________ potential energy
more
153 The energy needed to raise the temperature 1 kg of a material by 1ᵒC is the __________
specific heat capacity
154 The average kinetic energy of particles is known as the ___________
temperature
155 The amount of energy required to change the state of one kilogram of a substance with no change in temperature is the …?
specific latent heat
156 Latent heat of fusion is for changing…? solid to liquid
157 Latent heat of vaporisation is for changing….? liquid to vapour (gas)
158 Increasing temperature ______________ pressure in a gas if volume is constant
increases
159 The force exerted by gas on a surface as the particles collide with it is known as….?
gas pressure
160 State the units of density kg/m3
161 State the units of volume m3
162 Sketch the heating curve for water
163 Draw a particle diagram for a solid
164 Draw a particle diagram for a liquid
165 Draw a particle diagram for a gas
166 Why doesn't temperature increase during melting?
Energy is being used to weaken forces between particles
167 Why doesn't temperature increase during evaporation
Energy is being used to weaken forces between particles
168 Why does temperature of a substance increase as it is heated?
Particles gain more kinetic energy and temperature is a measure of kinetic energy
169 Particles are arranged regularly in a ….? solid
170 Particles are arranged randomly, but touching in a …?
of an atom Atoms are very small, having a radius of about 1 × 10-10 metres.
The basic structure of an atom is a positively charged nucleus composed of both protons and neutrons surrounded by negatively charged electrons.
The radius of a nucleus is less than 1/10 000 of the radius of an atom. Most of the mass of an atom is concentrated in the nucleus.
The electrons are arranged at different distances from the nucleus (different energy levels). The electron arrangements may change with the absorption of electromagnetic radiation (move further from the nucleus; a higher energy level) or by the emission of electromagnetic radiation (move closer to the nucleus; a lower energy level).
In an atom the number of electrons is equal to the number of protons in the nucleus. Atoms have no overall electrical charge.
All atoms of a particular element have the same number of protons. The number of protons in an atom of an element is called its atomic number.
The total number of protons and neutrons in an atom is called its mass number.
Atoms of the same element can have different numbers of neutrons; these atoms are called isotopes of that element.
Atoms turn into positive ions if they lose one or more outer electron(s).
Students should be able to relate differences between isotopes to differences in conventional representations of their identities, charges and masses.
The development of the model of the atom
New experimental evidence may lead to a scientific model being changed or replaced.
Before the discovery of the electron, atoms were thought to be tiny spheres that could not be divided.
The discovery of the electron led to the plum pudding model of the atom. The model suggested that the atom is a ball of positive charge with negative electrons embedded in it.
The results from the alpha particle scattering experiment led to the conclusion that the mass of an atom was concentrated at the centre (nucleus) and that the nucleus was charged. This nuclear model replaced the plum pudding model.
Niels Bohr adapted the nuclear model by suggesting that electrons orbit the nucleus at specific distances. The theoretical calculations of Bohr agreed with experimental observations.
Later experiments led to the idea that the positive charge of any nucleus could be subdivided into a whole number of smaller particles, each particle having the same amount of positive charge. The name proton was given to these particles.
The experimental work of James Chadwick provided the evidence to show the existence of neutrons within the nucleus. This was about 20 years after the nucleus became an accepted scientific idea.
why the new evidence from the scattering experiment led to a change in the atomic model
the difference between the plum pudding model of the atom and the nuclear model of the atom.
Radioactive decay and
nuclear radiation
Some atomic nuclei are unstable. The nucleus gives out radiation as it changes to become more stable. This is a random process called radioactive decay.
Activity is the rate at which a source of unstable nuclei decays
Activity is measured in becquerel (Bq)
Count-rate is the number of decays recorded each second by a detector (eg Geiger-Muller tube).
The nuclear radiation emitted may be: • an alpha particle (α) – this consists of two neutrons and two protons, it is the same as a helium nucleus • a beta particle (β) – a high speed electron ejected from the nucleus as a neutron turns into a proton
• a gamma ray (γ) – electromagnetic radiation from the nucleus • a neutron (n).
Required knowledge of the properties of alpha particles, beta particles and gamma rays is limited to their penetration through materials, their range in air and ionising power.
Students should be able to apply their knowledge to the uses of radiation and evaluate the best sources of radiation to use in a given situation.
Nuclear equations
Nuclear equations are used to represent radioactive decay.
beta decay does not cause the mass of the nucleus to change but does cause the charge of the nucleus to increase.
Students should be able to use the names and symbols of common nuclei and particles to write balanced equations that show single alpha (α) and beta (β) decay. This is limited to balancing the atomic numbers and mass numbers.
The emission of a gamma ray does not cause the mass or the charge of the nucleus to change.
Half-lives and the random
nature of radioactive
decay
Radioactive decay is random.
The half-life of a radioactive isotope is the time it takes for the number of nuclei of the isotope in a sample to halve, or the time it takes for the count rate (or activity) from a sample containing the isotope to fall to half its initial level.
Explain the concept of half-life and how it is related to the random nature of radioactive decay.
determine the half-life of a radioactive isotope from given information.
Radioactive contamination
Radioactive contamination is the unwanted presence of materials containing radioactive atoms on other materials. The hazard from contamination is due to the decay of the contaminating atoms. The type of radiation emitted affects the level of hazard.
Irradiation is the process of exposing an object to nuclear radiation. The irradiated object does not become radioactive.
Students should be able to compare the hazards associated with contamination and irradiation.
Suitable precautions must be taken to protect against any hazard that the radioactive source used in the process of irradiation may present.
Students should understand that it is important for the findings of studies into the effects of radiation on humans to be published and shared with other scientists so that the findings can be checked by peer review.
Background radiation
Background radiation is around us all of the time. It comes from: • natural sources such as rocks and cosmic rays from space • man-made sources such as the fallout from nuclear weapons testing and nuclear accidents.
The level of background radiation and radiation dose may be affected by occupation/location.
Radiation dose is measured in sieverts (Sv)
1000 millisieverts (mSv) = 1 sievert (Sv)
Different half-lives of
radioactive isotopes
Radioactive isotopes have a very wide range of half-life values.
Students should be able to explain why the hazards associated with radioactive material differ according to the half-life involved.
Uses of nuclear
radiation
Nuclear radiations are used in medicine for the: • exploration of internal organs • control or destruction of unwanted tissue.
describe and evaluate the uses of nuclear radiations for exploration of internal organs, and for control or destruction of unwanted tissue
evaluate the perceived risks of using nuclear radiations in relation to given data and consequences.
Nuclear fission
Nuclear fission is the splitting of a large and unstable nucleus (eg uranium or plutonium).
Spontaneous fission is rare. Usually, for fission to occur the unstable nucleus must first absorb a neutron.
The nucleus undergoing fission splits into two smaller nuclei, roughly equal in size, and emits two or three neutrons plus gamma rays. Energy is released by the fission reaction.
All of the fission products have kinetic energy.
The neutrons may go on to start a chain reaction.
The chain reaction is controlled in a nuclear reactor to control the energy released. The explosion caused by a nuclear weapon is caused by an uncontrolled chain reaction.
draw/interpret diagrams representing nuclear fission and how a chain reaction may occur.
Nuclear fusion Nuclear fusion is the joining of two light nuclei to form a heavier nucleus. In this process some of the mass may be converted into the energy of radiation.
Complete this table about what you know about the different types of radiation
3.0 The discovery of the electron led to the plum pudding model to explain the structure of the atom.
The results from the alpha particle scattering experiment led to
the plum pudding model being replaced by the nuclear model.
TOP TIP: In the exam if you are asked to compare two things or describe the similarities and differences. Draw up a table to lay out your answer clearly and make sure you have enough points to make sure you gain all the marks.
And DON’T BOTHER writing the same thing but in reverse. E.g Nuclear model has shells, plum pudding does not have shells, you will only score 1 mark for this
3.1 Describe the differences between the two models of the atom.
[6 marks]
KEY WORD: What is the definitions of an isotope? Write it in the space below.
4.0 There are many isotopes of the element technetium (Tc).
4.1 What do the nuclei of different technetium isotopes have in common?
4.4 Technetium-99 is used by doctors as a medical tracer. In hospitals it is produced inside a technetium generator by the decay of molybdenum-99 nuclei.
The graph below shows how the number of nuclei in a sample of molybdenum-99 changes with time as the nuclei decay.
Revision Checklist – use this list to identify your areas of strength and weakness to focus your revision
Specification Statement Revised RAG
Recognise expressions given in standard form Relate differences between isotopes to differences in conventional representations of their identities,
charges and masses
Show an understanding of why and describe how scientific methods and theories develop over time
Describe why the new evidence from the scattering experiment led to a change in the atomic model
Describe the difference between the plum pudding model of the atom and the nuclear model of the atom Recall properties of alpha particles, beta particles and gamma rays is limited to their penetration through
materials, their range in air and ionising power
Apply knowledge to the uses of radiation and evaluate the best sources of radiation to use in a given situation
Use the names and symbols of common nuclei and particles to write balanced equations that show single alpha (α) and beta (β) decay
Explain the concept of half-life and how it is related to the random nature of radioactive decay
Determine the half-life of a radioactive isotope from given information (HT only) Calculate the net decline, expressed as a ratio, in a radioactive emission after a given number of
half-lives
Compare the hazards associated with contamination and irradiation Understand that it is important for the findings of studies into the effects of radiation on humans to be
published and shared with other scientists so that the findings can be checked by peer review
Keywords - Use these words to produce a glossary of key terms for this chapter
The topic in pictures – these images are hyperlinked to useful parts of the BBC Bitesize website – use them to access
1. What happens to an atom when it has an outer electron removed (e.g. by ionising radiation)
2. What is the name given to the process when radiation is released as an unstable nucleus becomes more
stable?
3. What is radioactivity measured in?
4. What is an alpha particle?
5. What is a beta particle?
6. What change takes place in a nucleus when a beta particle is emitted?
7. What electromagnetic radiation can be released from the nucleus of a radioactive sample?
8. How is an alpha particle represented in nuclear equations?
9. How is a beta particle represented in nuclear equations?
10. What is the time taken for the number of nuclei of an isotope in a sample to halve known as?
11. What is the presence of radioactive materials on or in other objects known as?
12. What is the process of exposing an object to nuclear radiation without causing it to become radioactive
known as?
Gamma
Geiger counter
Ionising
Penetration
Irradiation
Contamination
Nuclear model
Plumb pudding
Half life
Background radiation
Grade 5
Radiation and Half-life Worksheet
1. Where does nuclear radiation come from?
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
2. What are alpha particles made of?
……………………………………………………………………………………………………………
3. What are the properties of gamma radiation?
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
4. Complete the following nuclear decay equations. Add the mass numbers and atomic numbers of
the daughter element (shown as X).
5. A student is given a low-level radioactive source, but the label has gone missing from the lead-
lined box it is kept in. Design an experiment to find out whether the source is an alpha, beta or
gamma emitter using a Geiger-counter and a range of materials.
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
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6. Explain what is meant by ionizing radiation.
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
7. Explain how ionizing radiation can affect living cells.
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
8. Gamma radiation may be used to treat cancer. The diagram below shows many gamma sources
directed at a single point. What is the advantage of this method compared with using a single
beam?
…………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
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9. Why is gamma radiation used as a tracer in the body rather than alpha radiation?
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
10. What is half-life?
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
11. Use the graph to calculate the half life of a sample.
Half-life= ………………
12. Carbon-14 has a half-life of 5,700 years. If a sample of freshly cut wood has a count rate of 10
counts per minute, and a second piece of wood has a count rate of
2.5 counts per minute, how old is the second piece of wood?
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
13. Would long or short half-life materials be appropriate in the following situations?
long or short half-
life? reason
smoke alarm
fuel for nuclear power
gamma knife for use
in hospital
radioactive source for
use in school
co
un
ts p
er
min
ute
time (days)
These questions and answers are fundamental to understanding this topic. Use these questions and answers to practice and revise from. Make que cards or simply cover the right hand side of the page and reveal each answer.
Question Answer R/A/G
172 Define atom The smallest part of an element that can exist.
173 All substances are made up of…? atoms
174 The radius of an atom is …? 0.1 nm (1 x 1010 m)
175 The overall charge on an atom is… zero/neutral
176 Define element Contains only one type of atom
177 Substances found in the periodic table are…? elements
178 Approximately how many elements are there? 100
179 Define isotope An atom of the same element with different numbers of neutrons
180 Define radioactive decay An unstable nucleus changes to become more stabe and gives out radiation
181 We cannot predict when a given atom will decay, this means that radioactive deacy is ….?
random
182 Define activity Rate at which decay occurs
183 What are the units of activity? Becquerels (Bq)
184 Define count rate Number of decays recorded each second by a Geiger-Muller tube
185 Defne half life The time taken for number of radioactive nuclei in a sample to halve OR time taken for count rate (or activity) from a sample to fall to half its initial value
186 Define contamination The unwanted presence of materials containing radioactive atoms
187 Define irradiation When an object is exposed to radiation
188 Does an irradiatied object become radioactive itself?
no
189 The process of radiation removing electrons from atoms to form ions is called…?
ionisation
190 If ionisation happens in DNA it can cause ___________ which may result in ____________
mutations, cancer
191 Define peer review Checking of scientific results by other scientific experts
192 Define mass number The total number of protons and neutrons in an atom
193 Define atomic number The number of protons in an atom (number of electrons is the same in a neutral atom)
194 Electrons in atoms are located in ___________ energy levels
195 Absorption of radiation by an atom may result in ____________ moving to a ________________ energy level
electrons, higher
196 Emission of radiation from an atom may lead to _____________ moving to a ______________ energy level
electrons, lower
197 Who came up with the Plumb Pudding model of the atom
J J Thompson
198 Describe the Plumb Pudding model of the atom
A ball of positive charge with negative electrons embedded in it
199 Was the Plumb Pudding model correct? no
200 What experiment did Rutherford do? Alpha particle scattering
201 What did Rutherford's experiment reveal? Atoms have a central area of positive charge with electrons surrounding it
202 Who discovered that electrons are located in energy levels?
Niels Bohr
203 What did Jame Chadwick discover about the atom?
That the nucleus contains neutrons as well as protons
204 What did John Dalton contribute to our understanding of atomic theory?
Matter is made up of descrete, spherical particles, known as atoms
205 Name the three subatomic particles proton, neutron, electron
206 Which particles are located in the atoms nucleus
protons, neutrons
207 What is the charge of each subatomic particle? proton +1, neutron 0, electron -1
208 What is the mass of each subatomic particle? proton 1, neutron 1, elecrton ≈ 0
209 Name the three types of radiation alpha, beta and gamma
210 What is an alpha particle? two protons and two neutrons
211 What is a beta particle? an electron
212 What is gamma radiation? electromagnetic wave (NOT a particle)
213 What is the range of alpha radiation in air? short - 5 cm in air
214 What is the range of gamma radiation in air? unlimited in air
215 What's the range of beta radiation in air? medium - about 1 m
216 What will absorb (stop) alpha radiation? paper/skin
217 What will absorb (stop) beta radiation? about 5 mm aluminium
218 What will absorb (stop) gamma radiation? several centimetres of lead
219 What is the ionising power of alpha radiation? very high
220 What is the ionising power of beta radiation? medium
221 What is the ionising power of gamma radiation?
low
222 What is meant by the ionising power of radiation?
how likely it is to ionise atoms which it comes into contact with
223 How does alpha decay alter the mass number of the parent nucleus?
decreases by 4
224 How does alpha decay alter the atomic number of the parent nucleus?
decreases by 2
225 How does beta decay alter the mass number of the parent nucleus?
stays the same
226 How does beta decay alter the atomic number of the parent nucleus?
increases by 1
227 How does gamma radiation alter the mass and atomic number of the parent nucleus
unchanged (energy is released as the particles in the nucleus reorganise to a lower energy arrangement)
Science Faculty Physics 5: Forces Checklist
Forces RAG
foundation higher triple
Scalar and vector
quantities
Scalar quantities have magnitude only.
Vector quantities have magnitude and an associated direction.
A vector quantity may be represented by an arrow. The length of the arrow represents the magnitude, and the direction of the arrow the direction of the vector quantity.
Contact and non-contact
forces
A force is a push or pull that acts on an object due to the interaction with another object. All forces between objects are either: • contact forces – the objects are physically touching • non-contact forces – the objects are physically separated.
Examples of contact forces include friction, air resistance, tension and normal contact force.
Examples of non-contact forces are gravitational force, electrostatic force and magnetic force.
Force is a vector quantity.
Students should be able to describe the interaction between pairs of objects which produce a force on each object. The forces to be represented as vectors.
Gravity Weight is the force acting on an object due to gravity. The force of gravity close to the Earth is due to the gravitational field around the Earth.
The weight of an object depends on the gravitational field strength at the point where the object is.
Recall and apply weight = mass × gravitational field strength equation.
The weight of an object may be considered to act at a single point referred to as the object’s ‘centre of mass’.
The weight of an object and the mass of an object are directly proportional.
Resultant forces
A number of forces acting on an object may be replaced by a single force that has the same effect as all the original forces acting together. This single force is called the resultant force.
Students should be able to calculate the resultant of two forces that act in a straight line.
describe examples of the forces acting on an isolated object or system
Use free body diagrams to describe qualitatively examples where several forces lead to a resultant force on an object, including balanced forces when the resultant force is zero.
A single force can be resolved into two components acting at right angles to each other. The two component forces together have the same effect as the single force.
Students should be able to use vector diagrams to illustrate resolution of forces, equilibrium situations and determine the resultant of two forces, to include both magnitude and direction (scale drawings only).
Distance and displacement
Distance is how far an object moves and does not involve direction. It is a scalar quantity.
Displacement includes both the distance an object moves, measured in a straight line from the start point to the finish point and the direction of that straight line. Displacement is a vector quantity.
Express a displacement in terms of both the magnitude and direction.
Speed Speed does not involve direction. Speed is a scalar quantity.
The speed of a moving object is rarely constant. When people walk, run or travel in a car their speed is constantly changing.
The speed at which a person can walk, run or cycle depends on many factors including: age, terrain, fitness and distance travelled. Typical values may be taken as: walking 1.5 m/s; running 3 m/s; cycling 6 m/s.
Students should be able to recall typical values of speed for a person walking, running and cycling as well as the typical values of speed for different types of transportation systems
It is not only moving objects that have varying speed. The speed of sound and the speed of the wind also vary.
A typical value for the speed of sound in air is 330 m/s.
Students should be able to make measurements of distance and time and then calculate speeds of objects.
Students should be able to recall and apply s = v t equation.
Students should be able to calculate average speed for non-uniform motion.
Velocity The velocity of an object is its speed in a given direction. Velocity is a vector quantity.
Students should be able to explain the vector–scalar distinction as it applies to displacement, distance, velocity and speed.
The distance–
time relationship
If an object moves along a straight line, the distance travelled can be represented by a distance–time graph.
The speed of an object can be calculated from the gradient of its distance–time graph.
Students should be able to draw distance–time graphs from measurements and extract and interpret lines and slopes of distance–time graphs, translating information between graphical and numerical form.
Students should be able to determine speed from a distance–time graph.
If an object is accelerating, its speed at any particular time can be determined by drawing a tangent and measuring the gradient of the distance–time graph at that time.
Acceleration Students should be able to recall and apply acceleration = change in velocity/time taken equation.
An object that slows down is decelerating.
The acceleration of an object can be calculated from the gradient of a velocity–time graph.
draw velocity–time graphs from measurements and interpret lines and slopes to determine acceleration
Students should be able to apply final velocity2-initial velocity2 = 2 × acceleration × distance equation which is given on the Physics equation sheet.
Newton's First Law
If the resultant force acting on an object is zero and: • the object is stationary, the object remains stationary • the object is moving, the object continues to move at the same speed and in the same direction. So the object continues to move at the same velocity.
So, when a vehicle travels at a steady speed the resistive forces balance the driving force.
So, the velocity (speed and/or direction) of an object will only change if a resultant force is acting on the object.
Students should be able to apply Newton’s First Law to explain the motion of objects moving with a uniform velocity and objects where the speed and/or direction changes.
Newton's Second Law
The acceleration of an object is proportional to the resultant force acting on the object, and inversely proportional to the mass of the object.
Students should be able to recall and apply F=ma equation.
Students should be able to estimate the speed, accelerations and forces involved in large accelerations for everyday road transport.
Required practical activity 7
investigate the effect of varying the force on the acceleration of an object of constant mass, and the effect of varying the mass of an object on the acceleration produced by a constant force.
Newton's Third Law
Whenever two objects interact, the forces they exert on each other are equal and opposite.
Students should be able to apply Newton’s Third Law to examples of equilibrium situations.
Forces and breaking
The stopping distance of a vehicle is the sum of the distance the vehicle travels during the driver’s reaction time (thinking distance) and the distance it travels under the braking force (braking distance). For a given braking force the greater the speed of the vehicle, the greater the stopping distance.
Reaction times vary from person to person. Typical values range from 0.2 s to 0.9 s.
driver’s reaction time can be affected by tiredness, drugs and alcohol. Distractions may also affect a driver’s ability to react.
explain methods used to measure human reaction times and recall typical results
interpret and evaluate measurements from simple methods to measure the different reaction times of students
evaluate the effect of various factors on thinking distance based on given data.
Factors affecting braking distance
The braking distance of a vehicle can be affected by adverse road and weather conditions and poor condition of the vehicle.
Adverse road conditions include wet or icy conditions. Poor condition of the vehicle is limited to the vehicle's brakes or tyres.
explain the factors which affect the distance required for road transport vehicles to come to rest in emergencies, and the implications for safety
estimate how the distance required for road vehicles to stop in an emergency varies over a range of typical speeds.
When a force is applied to the brakes of a vehicle, work done by the friction force between the brakes and the wheel reduces the kinetic energy of the vehicle and the temperature of the brakes increases.
The greater the speed of a vehicle the greater the braking force needed to stop the vehicle in a certain distance.
The greater the braking force the greater the deceleration of the vehicle. Large decelerations may lead to brakes overheating and/or loss of control.
estimate the forces involved in the deceleration of road vehicles in typical situations on a public road.
explain the dangers caused by large decelerations
Momentum is a property
of moving objects
Students should be able to recall and apply momentum = mass × velocity equation.
Conservation of
momentum
In a closed system, the total momentum before an event is equal to the total momentum after the event.
describe and explain examples of momentum in an event, such as a collision
Forces
6-5 Forces – Trilogy
1.0 The distance taken for a car to stop after an emergency depends on two things:
The thinking distance: how far the car travels while the driver processes the information.
The braking distance: how far the car travels after the driver presses the break.
1.1 Each distance is affected by different factors.
Tick the boxes to show whether each factor affects the thinking distance, the braking distance or both.
[2 marks]
Factor Thinking distance
Braking distance
Both
Speed of car
Water on road
Driver’s tiredness
Driver’s alcohol consumption
Condition of car’s brakes
Read and try the equations: https://mathsmadeeasy.co.uk/gcse-maths-revision/velocity-time-graphs-gcse-revision-
and-worksheets/
What is happening at each of these points on the graph?
These questions and answers are fundamental to understanding this topic. Use these
questions and answers to practice and revise from. Make que cards or simply cover the
right hand side of the page and reveal each answer.
228 A value with magnitude only is a ________? scalar
229
A value with magnitude and direction is a
____________? vector
230
Distance an speed are examples of _________
quantities scalar
231
Force, displacement and velocity are examples of
__________ quantities vector
232 What is a contact force? A force between two object which are touching
233 What ia a non-contact force?
A force between objects which are separated by
space.
234 Give two examples of contact forces e.g. friction, air resistance
235 List three non-contact forces gravitational, electrostatic, magnetic
236 Define weight The force ofgravity acting on an object's mass
237 What device is used to measure weight? A newtonmeter
238
What is the name of the single point at which an
object's mass appears to act? centre of mass
239 The center of mas of an object is…
the single point at which the objects weight appears
to act.
240
The single force which has the same effect as the
combination of all the different forces acting on an
object is the ______________ _______________. resultant force
241 Work is done when an object is …. … moved through a distance
242
Moving objects with mass are said to have
__________? momentum
243 State the law of conservation of momentum
In a closed system the total momentum before an
event is equal to the total momentum after an event.
244
State the equation which links gravitaional field
strength, mass and weight W=mg
245
State the equation which links distance, force and
work done W=Fs
246
State the equation which links extension, force and
spring constant F=ke
247
State the equation which links distance, speed and
time s=vt
248
State the equation which links acceleration, change
in velocity and time taken a Δv/t
249
State the equation which links acceleration, mass
and resultant force F = ma
250
State the equation which links mass, momentum
and velocity ρ = mv
251 What is the unit of weight? Newtons (N)
252 What is the unit of mass? kilograms (kg)
253 What is unit of gravitational field strength? newtons per kilogram (N/kg)
254 What is the unit of work done? Joules (J)
255 What is the unit of force? Newtons (N)
256 What is the unit of distance? meters (m)
257 What is the unit of the spring constant? Newtons per meter (N/m)
258 What is the unit of the spring extension? Metres (m)
259 What is the unit of speed or velocity? metres per secons (m/s)
260 What are the units of acceleration? metres per second squared (m/s2)
262
When a spring is stretched and can then return to
its original length it is known as __________
_______________ elastic deformation or elastic behaviour
263
When a spring is stretched and its length is
permanently altered it is known as ___________
____________ Inelastic deformation or inelastic behaviour
264 The limit of proportionallity of a spring is…
the length a spring can be stretched to before it no
longer returns to its original length
265
Sketch the Force (y) -Extension (x) curve for
stretching a spring from no force to beyond its
elastic limit. teacher to draw on board…
266
The stopping distance of a vehicle is the sum of the
….. thinking and breaking distances
267
The distance a vehicle travels while the driver is
reacting is the … thinking distance
268
The distance a vehicle travels which the driver is
breaking is the … breaking distance
269 Reaction time is… the time it takes a driver to react
270 A typical reaction time is … 0.2-0.9 s
271 Factors which influence reaction time are… tiredness, drug, alcohol, distractions
272 Fctors which affect breaking distance are … weather conditions, conditions of breaks and tyres
273 Both thinking and breaking distance are affected by
speed of vehicle
which factor?
274
The greater the speed of a vehicle, the _________
the force required to stop the vehicle greater
275
The distance and object moves and the direction in
which it moves is known as the _________ displacement
276
The speed of an object in a particular derection is
its ___________ velocity
277
The change of an objects speed in a given time is
the _________ acceleration
280
On a distance time graph a straight line
represents… constant speed
281
On a distance time graph a upward curve
represents… acceleration
282
On a distance time graph a curved line becoming
horizontal represents… decelleration
283
On a distance time graph a horizontal line
represents… stationary
284
On a distance time graph the gradient is used to
calculate the … speed or velocity
292 A typical walking speed is … 1.5 m/s
293 A typical running speed is … 3 m/s
294 A typical cycling speed is … 6 m/s
295 Sound in air travels at … 330 m/s
296 State Newton's First Law
The velocity of an object will only change if a resultant
force is acting on the object.
297 f balanced forces act on a moving object it will … continue to travel at a constant speed
298
If balanced forces act on a stationary object it will
… remain stationary
299 State Newton's Second Law
Force = mass x acceleration (The acceleration of an
object is proportional to the resultant force acting on
the object, and inversley proportional to the mass of
the object)
300 State Newton's Third Law
Whenever two objects interact, the forces they exert
on each other are equal and opposite
Science Faculty Physics 6: Waves Checklist
Electromagnetic spectrum RAG foundation higher triple
Electromagnetic waves are transverse waves that transfer energy from the source of the waves to an absorber.
Electromagnetic waves form a continuous spectrum and all types of electromagnetic wave travel at the same velocity through a vacuum (space) or air.
The waves that form the electromagnetic spectrum are grouped in terms of their wavelength and their frequency. Going from long to short wavelength (or from low to high frequency) the groups are: radio, microwave, infrared, visible light (red to violet), ultraviolet, Xrays and gamma rays.
Students should be able to give examples that illustrate the transfer of energy by electromagnetic waves.
investigate how the amount of infrared radiation absorbed or radiated by a surface depends on the nature of that surface.
Changes in atoms and the nuclei of atoms can result in electromagnetic waves being generated or absorbed over a wide frequency range. Gamma rays originate from changes in the nucleus of an atom.
Ultraviolet waves, X-rays and gamma rays can have hazardous effects on human body tissue. The effects depend on the type of radiation and the size of the dose. Radiation dose (in sieverts) is a measure of the risk of harm resulting from an exposure of the body to the radiation.
1000 millisieverts (mSv) = 1 sievert (Sv)
Students should be able to draw conclusions from given data about the risks and consequences of exposure to radiation.
Ultraviolet waves can cause skin to age prematurely and increase the risk of skin cancer. X-rays and gamma rays are ionising radiation that can cause the mutation of genes and cancer.
Electromagnetic waves have many practical applications. For example: • radio waves – television and radio • microwaves – satellite communications, cooking food • infrared – electrical heaters, cooking food, infrared cameras • visible light – fibre optic communications • ultraviolet – energy efficient lamps, sun tanning • X-rays and gamma rays – medical imaging and treatments.
Waves may be either transverse or longitudinal.
The ripples on a water surface are an example of a transverse wave.
Longitudinal waves show areas of compression and rarefaction. Sound waves travelling through air are longitudinal.
Students should be able to describe the difference between longitudinal and transverse waves.
Students should be able to describe evidence that, for both ripples on a water surface and sound waves in air, it is the wave and not the water or air itself that travels.
Students should be able to describe wave motion in terms of their amplitude, wavelength, frequency and period.
Students should be able to show how changes in velocity, frequency and wavelength, in transmission of sound waves from one medium to another, are inter-related.
The amplitude of a wave is the maximum displacement of a point on a wave away from its undisturbed position.
The wavelength of a wave is the distance from a point on one wave to the equivalent point on the adjacent wave.
The frequency of a wave is the number of waves passing a point each second.
Students should be able to apply T = 1/f equation which is given on the Physics equation sheet.
Students should be able to recall and apply v f λ equation.
identify amplitude and wavelength from given diagrams
describe a method to measure the speed of sound waves in air
describe a method to measure the speed of ripples on a water surface.
make observations to identify the suitability of apparatus to measure the frequency, wavelength and speed of waves in a ripple tank and waves in a solid and take appropriate measurements.
6-6 Waves – Trilogy
COMPLETE: write in the boxes below the parts of the Electromagnetic spectrum.
1.0 Figure 1 shows an incomplete electromagnetic spectrum.
Figure 1
A microwaves B C ultraviolet D gamma
1.1 Which position are X-rays found in?
Tick one box.
[1 mark]
A
B
C
D
1.2 Which three waves can cause ionisation?
Tick three boxes.
[1 mark]
Gamma rays
Infrared
Microwaves
Radio waves
Visible light
Ultraviolet
X-rays
1.3 Electromagnetic waves have many practical uses.
Draw one line from each type of electromagnetic wave to its use.
1. Suggest how the amount of energy transferred by a wave changes as the amplitude increases.
2. When the frequency of a wave doubles, what happens to its wavelength?
3. Make a sketch of a transverse wave to explain what is meant by the terms (a) amplitude and (b) wavelength.
4. f energy is being transmitted away from the Sun, why isn’t the Sun continually cooling down?
5. Suggest what equipment you could use to measure the wavelength of a water wave, and how you should set
it up.
6. Describe what you would observe if a sound wave crossed from air into a material where it was
a) completely absorbed
b) partly absorbed and partly transmitted.
7. What are the similarities and differences between transverse and longitudinal waves?
8. Explain how waves in the electromagnetic spectrum are different from other waves.
9. What properties do all electromagnetic waves have in common?
10. Water waves are affected by the depth of the water they travel through. Do the waves travel faster in deep
or shallow water? Explain your answer.
11. Describe the similarities and differences between gamma rays and X-rays.
12. State three uses of ultraviolet radiation.
13. Suggest two advantages of using a microwave oven instead of an infrared oven.
These questions and answers are fundamental to understanding this topic. Use these
questions and answers to practice and revise from. Make que cards or simply cover the
right hand side of the page and reveal each answer.
302
The maximum displacement of a point on a wave
away from its undeisturbed position is the… Amplitude
303
The distance from a point on one wave to the
equivalent point on the next wave is the … wavelength
304
The number of waves passing a point each second is
the… Frequency
305 Name an example of a longitudinal wave Sound
306 Name an example of a transverse wave light, water, any electromagnetic
307
Oscillations are along the same direction as the
direction of travel is a _________ wave longitudinal
308
Oscillations are at right angles to the direction of
travel in a ____________ wave transverse
309
The time needed for one wave to pass a given point is
the… period
310
The region in a longitudinal wave where particles are
closest together is a … compression
311
The region in a longitudinal wave where particels are
furthest apart is a… rarefaction
312
An object is said to _________ radiation when energy
from an EM wave is taken up by the object absorb
313
An object is said to _________ radiation when a wave
can pass through the object transmit
314
The process taking place when a wave bounces off of
a surface reflection
315
The process taking place when a wave enters a
different density medium and changes direction refracion
316
Refraction changes both the _________ and
___________ of a wave direction and speed
317 Which two angles are equal in reflection angle of incidence and angle of reflection
318
Draw a transverse wave and label the wavelength and
amplidtue
319 Draw a longitudinal wave and label the wavelength
320
Write the equation linking frequency, wavelength and
wave speed v fλ
321 What is the unit of frequency? Hertz (Hz)
322 What is the unit of wavelength? metres (m)
323 What is the unit of wave speed? metres per second (m/s)
324 What is the speed of elecrtomagnetic radiation? 300 000 000 m/s
325
What is the EM radiation with the shortest
wavelength? gamma
326
What is the EM radiation with the longest
wavelength? Radio
327 What is the EM radiation with the highest frequency? Gamma
328 What is the EM radiation with the lowest frequency? Radio
329 List the EM spectrum from long to short wavelength.
Radio, microwave, infrared, visible, UV, X-rays,
gamma
330 Can EM waves travel through space? yes
331 Can sound waves travel through space? no
332 Does a sound wave travel faster in water or air? water
333 Name a use of radio waves TV and radio transmission
334 What EM wave is used for satellite communication? microwave
335 Give one use of microwaves cooking food
336 Give two uses of IR radiation electrical heaters, infrared cameras
337 Give a use of visible radiation Fibre optic communications
338 Which radiation is used in sun tanning? UV
339 Give one use of X-rays. Medical imaging
340 Give one use of gamma rays Medical treatments
341 Why are X-rays good for taking images of bone?
absorbed by bone but transmitted through soft
tissue
342 Why are gamma rays used in medical treatment? Can kill cancer cells
343 What are the risks of exposure to UV radiation? Premature skin aging, increased risk of skin cancer
344 What are the risks of exposure of X-rays?
X-rays are ionising so can cause mutations which
may result in cancer
345 What are the risks of exposure to gamma rays?
Gamma rays are ionising so can cause mutations
which may result in cancer
Science Faculty Physics 7: Magnetism Checklist
Magnetism check
foundation higher triple
Poles of a magnet
The poles of a magnet are the places where the magnetic forces are strongest. When two magnets are brought close together they exert a force on each other. Two like poles repel each other. Two unlike poles attract each other. Attraction and repulsion between two magnetic poles are examples of non-contact force.
A permanent magnet produces its own magnetic field. An induced magnet is a material that becomes a magnet when it is placed in a magnetic field. Induced magnetism always causes a force of attraction. When removed from the magnetic field an induced magnet loses most/all of its magnetism quickly.
describe the attraction and repulsion between unlike and like poles for permanent magnets
describe the difference between permanent and induced magnets.
Magnetic fields
The region around a magnet where a force acts on another magnet or on a magnetic material (iron, steel, cobalt and nickel) is called the magnetic field.
The force between a magnet and a magnetic material is always one of attraction.
The strength of the magnetic field depends on the distance from the magnet. The field is strongest at the poles of the magnet.
The direction of the magnetic field at any point is given by the direction of the force that would act on another north pole placed at that point. The direction of a magnetic field line is from the north (seeking) pole of a magnet to the south(seeking) pole of the magnet.
magnetic compass contains a small bar magnet. The Earth has a magnetic field. The compass needle points in the direction of the Earth’s magnetic field.
describe how to plot the magnetic field pattern of a magnet using a compass
draw the magnetic field pattern of a bar magnet showing how strength and direction change from one point to another
explain how the behaviour of a magnetic compass is related to evidence that the core of the Earth must be magnetic
Electromagnetism
When a current flows through a conducting wire a magnetic field is produced around the wire. The strength of the magnetic field depends on the current through the wire and the distance from the wire.
Shaping a wire to form a solenoid increases the strength of the magnetic field created by a current through the wire. The magnetic field inside a solenoid is strong and uniform.
The magnetic field around a solenoid has a similar shape to that of a bar magnet. Adding an iron core increases the strength of the magnetic field of a solenoid. An electromagnet is a solenoid with an iron core.
describe how the magnetic effect of a current can be demonstrated
draw the magnetic field pattern for a straight wire carrying a current and for a solenoid (showing the direction of the field)
explain how a solenoid arrangement can increase the magnetic effect of the current.
6-7 Magnetism and electromagnetism – Trilogy
1.0 This question is about magnets.
1.1 Which statements apply to permanent magnets, which apply to electromagnets and which apply to both?
Tick the correct boxes.
[2 marks]
Permanent magnets
Electromagnets Both
Need an electric current to work
Have a constant magnetic field
Can be turned off
Have north and south poles
Often contain a coil of wire
1.2 What is an induced magnet?
Tick the correct box.
[1 mark]
A permanent magnet made by passing a current through a piece of steel
A temporary magnet made by repeatedly heating a piece of steel
A permanent magnet made by repeatedly stroking a piece of steel with a magnet
A temporary magnet made by touching a piece of steel with another magnet
WATCH: https://www.youtube.com/watch?v=DMO373nDp8M&t=58s 1.3 Describe how to find the direction of the magnetic field around a permanent magnet using a
1. Suggest how you know whether an object is a magnet when you bring another magnet close to it.
2. Explain why the north pole of a compass is often called the north-seeking pole.
3. A wire goes into the plane of a page. Draw a diagram to show the magnetic field and its direction around the
wire.
Keyword Definition
Magnetic field
Induced magnet
Permanent magnet
Magnetic material
Pole
Solenoid
Electromagnet
Current
Grade 5 Questions
1 Magnetic field patterns
a) Sketch the magnetic field around a bar magnet.
b) What is a neutral point?
_________________________________________________
c) Sketch the magnetic field around the two bar magnets shown below. Mark any neutral points with an ‘X’.
d) Sketch the magnetic field pattern around a straight wire carrying a current as shown below.
2) Adding magnetic fields
The diagram shows a wire carrying a current between two magnetic poles.
a) Sketch the magnetic field due to the current in the wire, when viewed from above.
b) Sketch the magnetic field due to the magnetic poles, when viewed from above.
c) Sketch the resultant magnetic field due to the current in the wire and the magnetic poles.
d) Write ‘strong’ where the magnetic field is strongest. e) Write ‘weak’ where the magnetic field is weakest. f) This unbalanced magnetic field results in a bigger force on the ‘strong’ side of the wire. Indicate by an
arrow on the diagram the direction in which the wire moves.
These questions and answers are fundamental to understanding this topic. Use these
questions and answers to practice and revise from. Make que cards or simply cover the
right hand side of the page and reveal each answer.
346
The places on a magnet where the magnetic forces are the
strongest are called the… poles
347 What is the definition of a magnetic field?
The area around a magnet where a force acts on
another magnet or magnetic material
348
The area around a magnet where a force acts on another
magnet or magnetic material in the… Magnetic field
349 Two like poles always ______ repel
350 Tow opposite poles always _______ attract
351 What is a permanent magnet? A magnet that produces its own magnetic field.
352 What is an induced magnet?
A magnetic material which becomes a magnet when
placed in a magnetic field.
353
A magnetic material which becomes a magnet when
placed in a magnetic field is a _______ _________ induced magnet
354
What type of magnet loses its magnetism when it is
removed from a magnetic field? induced magnet
355 Which three elements are magnetic? iron, cobalt and nickel
356 Draw the magnetic field around a bar magnet teacher to draw on board…
357 Give the name for the magnet created using a coil of wire solenoid
358
Where is the strongest field in an electromganet created
by a coil of wire? inside the coil
359
What two words describe the magnetic field within the coil
of a solenoid? strong and uniform
360 What is an electromagnet?
A solenoid containing an iron core which increases its
strength
361
What is an important property of a
solenoid/electromagnet as a magnet can be switched on and off with electric current
367 Give three ways of increasing the force of a solenoid.
Add iron core, increase number of coils of wire,
increase current, move magnetic material closer
370
What two methods can you use to obesrve the field
around a bar magnet? Iron filings or plotting compass
371
Draw the magnetic field between two like poles and two
non-like poles.
373 The right hand thumb rule shows relative direction of… current and magnetic field around a wire
EXAM ANSWERS
MARK SCHEME – 1. Energy
Qu No. Extra Information Marks
1.1 Gravitational potential 1
1.2 Kinetic 1
1.3 50 × 9.8 × 2 – Gravitational potential
½ × 50 × 6.2 × 6.2 – Kinetic Both required for the mark 1
1.4 Energy lost to the surroundings
Named example (eg air gained internal energy)
Accept heat / air got warmer / sound
1
1
Qu No. Extra Information Marks
2.1 Coal C
Natural gas B
Nuclear power E
Oil D
Renewable fuels A
2 marks for all four correct
1 mark for 2 correct 2
2.2
Level 3 Clear, coherently organised answer.
Clear understanding of the overall energy needs of the country.
Understands the need for a range of resources.
Discusses both renewable and non-renewable energy resources, making clear points about each.
5– 6
Level 2 Some structure to answer.
Some discussion of the overall energy needs of the country.
Discusses a range of resources, giving advantages and disadvantages, although these may not be coherently linked.
3– 4
Level 1 Limited structure to answer.
Some discussion of a number of resources with limited link to the overall energy needs of the country.
1– 2
Level 0 No relevant content. 0
Indicative content
Same or greater overall energy required and/or efficiency savings mean potentially less energy required.
• Fossil fuels plentiful in supply.
• Fossil fuels contribute to global warming.
• Unlikely to be time to set up new nuclear fuel plants.
• Renewable energy resources expensive to set up.
• Renewable energy resources can be inefficient.
• Wave, hydro and/or wind likely to be useful for the UK.
• Solar power less likely to be useful.
• Biomass has negatives in land use and fertilisers etc.
Ignore discussion of nuclear waste etc.
Qu No. Extra Information Marks
3.1 Length = 20cm
Extension = 10cm Both required for the mark 1
3.2 0.5 × 25 × (15×10-3 )2
0.0028125
2.81×10-3 (J)
If extension of 15 used, do not allow first mark. ECF allowed:
2812.5
2.81×103 (J)
1
1
1
3.3 Either:
Attempt to use value from 3.2:
Rearrange k = Epe/(0.5 × e2)
Substitute k = (2 × 2.81×10-3)
(0.5 × (15×10-3/2)2
k = 200 N/m
Or:
Algebraic manipulation:
Rearrange k = Epe/(0.5 × e2)
Substitute multiple values
k = 2Epe/(0.5 × (e/2)2)
Cancel and compare with original
knew = 8kold
= 200 N/m
Allow 199 N/m
Allow ECF
Allow rounding errors
1
1
1
(1)
(1)
(1)
Qu No. Extra Information Marks
4.1 29 J of energy wasted (from light bulb, heating the air)
OWTTE 1
4.2 Heating offices saves 13 J of energy
New powerlines save 2.5 J of energy
LED bulbs save 29.7 J of energy
So replace lightbulbs
Allow ECF for incorrect bulb wastage in 4.1
All three calculations for 1 mark
1
1
4.3 Use of:
1 / 30 = 0.034
(So not correct)
Allow ECF for incorrect bulb wastage in 4.1
No mark for conclusion.
1
1
4.4 12 × 0.8 = 9.6
Time = energy / power
300 / 9.6 = 31.25 s
Allow 0 or 1 dp
1
1
1
Qu No. Extra Information Marks
5.1
Level 3 Clear, coherently organised answer.
Method complete with clear understanding of the experimental requirements and how the data would be analysed.
5-6
Level 2 Some structure to answer.
Main steps in method covered, with some errors or omissions.
Limited expression of data analysis.
3-4
Level 1 Limited structure to answer.
Some steps described, with little or no control variables. No data analysis. 1-2
Level 0 No relevant content. 0
Indicative content
• Heat a known mass of water.
• To a known temperature.
• Transfer the water to a beaker lagged with the first material.
• Cover the beaker with a lid of the same material.
• Record the temperature and start a clock.
• Record the temperature drop after a fixed time.
• Repeat using the same mass of water with the other materials.
• Determine which material has the smallest temperature drop in a given time/longest time for a given temperature drop.
• This will be the most effective material.
Qu No. Extra Information Marks
6.1 Energy supplied = power × time
= 300 × 8 × 60
= 144 × 103 J
Temperature rise = 70°C
Mass = 0.45 kg
Specific heat capacity = E/(m.)
= 144 × 103/(0.45 × 70)
= 4.6 × 103 J/kg °C
1
1
1
6.2 Any two from:
• Loss of heat to surroundings
• Heat absorbed by the beaker
• Evaporation
• Inaccurate thermometer/clock/balance
2
MARK SCHEME – 2. Electricity
Qu No. Extra Information Marks
1.1 50 Hz 1
1.2 230 V 1
1.3 Live wire carries the (alternating) potential difference/voltage (from the supply)
Neutral wire completes the circuit
1
1
1.4 connection is made to earth
charge can flow through the body.
or
large potential difference across the body
Accept answer in terms of a complete circuit or establishing a path (for charge to flow)
1
1
1.5 P = (3)2 x 100
900 (W)
Allow one mark for P=I2V if substitution incorrect.
Allow 900 (W) with no working for 2 marks
1
1
Qu No. Extra Information Marks
2.1 battery, lamp and ammeter connected in series with variable resistor
voltmeter in parallel with (filament) lamp
1
1
2.2
Level 2: A detailed and coherent description of the experiment. The response provides a logical sequence.
3-4
Level 1: Simple description of the experiment with some steps missing. The response may not be in a logical sequence and may not lead to the collection of valid results.
1-2
Level 0: No relevant content. 0
Indicative content
• ammeter used to measure current
• voltmeter used to measure potential difference
• resistance of variable resistor altered to change current in circuit or change potential difference (across filament lamp)
• resistance (of filament lamp) calculated or R=V / I statement resistance calculated for a large enough range of different currents that would allow a valid conclusion about the relationship to be made
Qu No. Extra Information Marks
3.1 V = 0.025 × 75
1.9 (V)
Allow 1.9 (V) with no working for 2 marks
1
1
3.2 total resistance = 6 / 0.025
R = 240 - 225
= 15 (Ω)
1
1
1
3.3 resistance decreases
current increases
1
1
Qu No. Extra Information Marks
4.1
battery in series with bulb and ammeter
voltmeter in parallel with the bulb
variable resistor
or
variable power supply
1
1
1
4.2 correct pair of current readings at the same pd therefore current in lamp A is twice the current in lamp B so lamp A is twice as powerful and lamp B (hence is twice as bright)
eg at 10 V, IA = 0.74A and IB = 0.37A
must refer to power/rate of energy transfer
1 1
1
4.3 R = V / I lowest R = 0.6 / 0.1 R = 6 Ω Highest R = 10 / 0.74 R = 13.5 Ω
Difference = 13.5 – 6 = 7.5 Ω
allow R= 1.0 / 0.16 R = 6.25 Ω (other values may be acceptable but the values from the graph must be when V ≤ 1V and the lamp can reasonably be assumed to be ohmic)
allow 7.25 Ω if consistent
1 1
1
MARK SCHEME – 3. Atomic Structure
Qu No. Extra Information Marks
1.1 solid 1
1.2 liquid 1
1.3 boiling
evaporation
1
1
1.4 the average kinetic energy of the particles 1
1.5 motion is random
range of speeds
or
range of directions
1
1
1.6 ρ = 0.032 / 0.026
ρ = 1.3 (kg/m3)
allow 1.28 (kg/m3)
allow 1.3 (kg/m3) with no working for 2 marks
1
1
Qu No. Extra Information Marks
2.1 food
fridge
surroundings
2 marks for all three in the correct place
1 mark for 2 or 1 in the correct place
2
2.2
Level 3: A detailed and coherent description of both the arrangement and motion of the particles in the different states of matter.
5-6
Level 2: A coherent description of both the arrangement and motion of the particles in the different states of matter.
3-4
Level 1: Simple description of the arrangement and / or motion of the particles in the different states of matter.
1-2
No relevant content 0
Indicative content
Solid
Particles closely packed in a regular pattern
Particles vibrate about a fixed position
Liquid
Particles closely packed in an irregular pattern
Particles are able to move relative to each other
Gas
Particles are widely spread in no pattern
Particles move randomly and rapidly.
2.3 Air molecules in fridge will have a greater speed.
because the air is at a greater temperature so greater kinetic energy
allow 2 marks for the converse.
1
1
Qu No. Extra Information Marks
3.1 conclusion is not correct
because 45 / 150 = 3.3
3.3 is less than 5
allow 40-50 for Tin
1
1
3.2 E = 1.023 x 450 x 10
E = 4 600 (J)
Answer to 2 sig. figs.
allow 2 marks for a correct answer to an incorrect number of sig figs
eg 4 604 (J)
allow 1 mark for an incorrect answer to an incorrect number of sig figs eg 4 603 (J) if substitution is correct
1
1
1
3.3 10 (minutes) 1
3.4 Correct line of best fit drawn 1
3.5 20 (°C) 1
3.6 gradient would be greater
because energy supplied per second would be greater.
so rate of increase of temperature would be greater.
or
more energy supplied (in 12 minutes)
so
greater final temperature (so greater temperature difference)
1
1
1
MARK SCHEME – 4. Atomic Structure
Qu No. Extra Information Marks
1.1
all three labels correct
allow 1 mark for 1 or 2 correct labels
2
1.2 has no electrons allow alpha has a positive(charge)
allow a helium (atom) has no (charge)
1
1.3 4
2
1
1
1.4 19.6 - 11.6
8 (hours)
allow ± 0.2 for each reading
allow ± 0.4 if consistent with values read from the graph
1
1
1.5 15.2 (hours) allow ± 0.2 1
Qu No. Extra Information Marks
2.1
allow 1 mark for each correct line
if more than one line is drawn from any type of radiation box then all of those lines are wrong
3
2.2 gamma
alpha
gamma
gamma and neutron
both required for 1 mark
1
1
1
1
Qu No. Extra Information Marks
3.1
Level 3 A detailed and coherent comparison of the arrangement of the particles in the different models.
5-6
Level 2: A detailed and coherent description of the arrangement of the particles in the different models.
3-4
Level 1: A simple description of the arrangement and /or a simple comparison of the arrangement of the particles in the different models.
1-2
No relevant content 0
Indicative content
nuclear model mass is concentrated at the centre / nucleus
plum pudding model mass is evenly distributed
nuclear model positive charge occupies only a small part of the atom
plum pudding model positive charge spread throughout the atom
nuclear model electrons orbit some distance from the centre / nucleus
plum pudding electrons embedded in the (mass) of positive (charge)
nuclear model the atom mainly empty space
plum pudding model is a ‘solid’ mass
Qu No. Extra Information Marks
4.1 (same) number of protons 1
4.2 beta
atomic / proton number increases (by 1)
or
number of neutrons decreases / changes by 1
1
1
4.3 time taken for number of radioactive nuclei to halve
or
(average) time taken for count-rate / activity to halve
1
4.4 1 half-life = 2.6 days
number of days = 7.8 days
1
1
4.5 Number of half-lives = 13/2.6
fraction = (½ x ½ x ½ x ½ x ½)
or (½)5
100 000 / 32
3125
safe
number is comparatively low, so low activity
unlikely to be substantial risk of contamination / irradiation.
or
unsafe
There are still some atoms of molybdenum left so some radiation emitted
therefore still a small risk.
no mark for safe / unsafe
1
1
1
1
1
1
MARK SCHEME – 5. Forces
Qu No. Extra Information Marks
1.1
Allow ticks in Thinking distance and Braking distance instead of both.
All five ticks correct: 2 marks
3 or 4 ticks correct: 1 mark
2
1.2 A and C
C and D
B and C
D and F
Both points required for each mark. 1
1
1
1
1.3
1 mark for Speed
1 mark for Velocity
2
1.4 Horizontal line above the x axis
Line drops to x axis
Line continues along x axis
Allow curved or straight line.
Do not allow vertical line
1
1
1
Qu No. Extra Information Marks
2.1 To allow for size of spring / to measure extension of the spring
1
2.2 Random error 1
2.3 Easier to read the scale / smaller parallax 1
2.4
Level 2: A detailed and coherent description of how to measure the spring constant. Answer includes multiple measurements and uses the gradient of a graph.
3-4
Level 1: A simple description of how to measure the spring constant. Likely to only include one reading and make reference to F = kx.
1-2
No relevant content 0
Indicative content
Change weight on spring
Measure extension for each weight
Reference to table of results
Plot graph of extension (y-axis) against weight (x-axis) (or vice versa)
Gradient is 1 / spring constant (or gradient is spring constant if axes swapped)
Reference to F = kx / Hooke’s law
2.5
𝑥 = √𝐸
0.5 𝑘
= √1.95
7.8
= 0.5 m / 50 cm
Allow 2 marks for an answer of 0.25 m / 25cm (student has forgotten to square root)
Award 2 marks for 50 cm
Award 2 marks for correct answer to more than 2 significant figures.
1
1
1
Qu No. Extra Information Marks
3.1 Newton’s third law
Jetpack forces the water down
So water exerts an equal (magnitude) and opposite (direction) force on the jetpack (so it moves up)
1
1
1
3.2 Combined weight = 84 × 9.8 = 820 N
Resultant force = 1900 – 820 = 1100 N
Acceleration = F/m = 1100 / 84
= 13 m/s2
v2 = u2 + 2as = 0 + 2 x 13 x 5 = 130
v = 11 m/s
1
1
1
1
1
1
MARK SCHEME – 6. Waves
Qu No. Extra Information Marks
1.1 D 1
1.2 Gamma rays
Ultra violet
X-rays
All three required for the mark 1
1.3 Radio waves – Television transmissions
Visible light – Fibre optic communications
Gamma rays – Medical treatments
All three correct – 2 marks
Two correct – 1 mark
If more than one line from any wave, deduct a mark, minimum of zero marks.
2
Qu No. Extra Information Marks
2.1 W Horizontal distance labelled between two identical points on adjacent waves
A Vertical distance from peak or trough to mean
1
1
2.2 Transverse waves
Wave moving up and down while moving from left to right
1
1
2.3 4 waves / 2 seconds
= 2 (Hz)
1
1
2.4 0.5
s / seconds
Allow ecf rom 2.3 if T = 1/f clearly used 1
1
Qu No. Extra Information Marks
3.1 V = f λ = 10 000 000 000 x 0.02
= 200 000 000
= 2 × 108 m/s
If wrong number of zeros used in calculation, allow ecf.
1
1
1
3.2 (No) as all electromagnetic waves have the same speed.
Ignore reference to speed changing in air.
1
3.3 (No) as the eye cannot see microwaves
The light is visible light (from a bulb)
1
1
3.4
Level 3: A detailed and coherent description of how to carry out a safe investigation including clear description of equipment to use and explanation of the measurements to take.
5-6
Level 2: A detailed and coherent description which may be lacking in some details or includes elements which are unlikely to work well (for example lengths of time over 5 mins).
3-4
Level 1: A description of an experiment which is lacking in detail or is inherently unsafe. 1-2
No relevant content
Indicative content
Equipment used (does not need to be in a list):
- Beaker
- Measuring cylinder
- Water
- Thermometer
- Stop watch / use of microwave to time
- Microwave
Investigation
- Pour ~200ml cold water into a beaker
- Measure temperature
- Put in microwave for 30 seconds
- Stir then measure the temperature after
- Repeat for a range of times up to 3 mins
- Plot a graph of the results
Qu No. Extra Information Marks
4.1 (for both fibres) increasing the wavelength of light decreases and then increases the percentage / amount of light transmitted
(for both fibres) the minimum transmission happens at 5 (x 10-7 metres)
the shorter fibre transmits a greater percentage of light (at the same wavelength)
1
1
1
4.2 f = c / λ
= 6 x 1014 Hz
1
1
4.3 Light refracts at boundary between cladding and core
Light changes speed / slows down in cladding
1
1
MARK SCHEME – 7. Electromagnetism
Qu No. Extra Information Marks
1.1 Need an electric current to work
Electromagnets
Have a constant magnetic field
Permanent magnets
Can be turned off Electromagnets
Have north and south poles
Both
Often contain a coil of wire
Electromagnets
All rows correct: 2 marks
3 or 4 rows correct: 1 mark
2
1.2 A temporary magnet made by touching a piece of steel with another magnet
1
1.3 Place compass at different points around the compass
Indication of how to draw eg note down the direction of the compass at each point around the magnet / compass points along field lines
Join each individual direction to form field lines
Accept clearly labelled diagram for any or all points
1
1
1
Qu No. Extra Information Marks
2.1
Level 2: A clear, coherent description of a safe experiment with given values of current (eg 0.5, 1.0, etc up to a maximum of about 5 A) and details of repeats. Includes letting the equipment cool down between experiments.
3-4
Level 1: A description of an experiment that would allow valid results to be obtained. May include currents higher than 5 A or omit details of number of readings to be taken or repeat measurements.
1-2
Indicative content
Set current to small value
Measure force on the iron disc
Repeat at regular increases of current
Repeat at least 2 more times
Allow equipment to cool between measurements
2.2 0.48 and 2.18
4.54
Allow +/- 0.2 for each reading
Allow ecf from marking point 1
1
1
2.3 (No)
The ratio increases with increased current
But as not in a linear fashion / example given
1
1
Qu No. Extra Information Marks
3.1 Magnetic field
Current
Force
Correct order only 1
1
1
3.2 Down onto the balance 1
3.3 From the front of the balance to the back of the balance
1
3.4 Reading would increase
As the magnetic flux density would increase
1
1
Qu No. Extra Information Marks
4.1 Arrow showing anticlockwise movement of the current
1
4.2 Direction: Change direction of current
Speed: Change amount of current
1
1
4.3 F = BIL = 3 ×10–2 × 0.5 × 0.04
= 6 × 10–4 (N)
1
1
Qu No. Extra Information Marks
5.1 To step up voltage (across the cables) /decrease the current (through the cables)
Reduces thermal energy transfer / Increases efficiency (in the cables)
Then step down voltage (across the cables) / increase the current (through the cables) (near users)
1
1
1
5.2 One of:
Politician is correct that magnetic field from underground cable drops off in short distance
Or
But it starts higher
No link to safety in the graph / no health effects