1.0 understanding physics

Physics Module Form 4 Chapter 1 – Introduction to physics GCKL 2011

1-1

U N D E R S T A N D I N G P H Y S I C S

Recognise the

concepts of

physics in

everyday objects

and natural

phenomena

1. Tick () the statements that are related to physics.

Blood circulation in our body is controlled by heart.

A large truck moves faster than a car because it has a more powerful engine.

We need water in our digestion system.

Orange juice is acidic because its taste is sour.

An object on a high building has a large potential energy.

When we heat water, its temperature increased.

We are sweating when our body metabolism is high.

Pure water has pH 7.

We cannot see object in dark

A ship is floating in water.

Human body coordination is controlled by hormone system.

Oxidation will act faster in acidic medium.

UNDERSTANDING BASE AND DERIVED QUANTITIES

Recognise

physical quantity

and unit

1. Identify Physical quantities, Magnitude, Units and Measuring instrument from the

statements below. Write them into the table below (next page).

A Ismail weigh a wooden block that has mass of 500 gram using a lever beam balance.

B Ong Beng Hock measures the length of a building which is 100 meter long using a

measuring tape.

C Siew Mei measures her body’s temperature using a digital thermometer and obtains

38C.

D Bathumalai determines the volume of water using a measuring cylinder and obtains

150 milliliter.

E Hanisah measures the diameter of a wire which is 1.26 millimeter using a

micrometer screw gauge.

F Vinisha takes the time of 20 oscillations of a pendulum using a stopwatch and

obtains 24.6 seconds.

Statement Physical quantity Magnitude Unit Measuring

instrument

A

B

C

D

E

F

1.1

1.2


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Define base

quantities and

derived quantities

are

2. Identify base quantities and derived quantity from the equation below.

(a) Volume = length x length x length

Base quantity = (i) _________________

Derived quantity = (i) _________________

(b) Area = length x length

Base quantity = (i) _________________


(c)

Base quantity = (i) _________________ (ii) ____________________


(i) Base quantity is physical quantity that __________ be derived from any quantities.

(ii) Derived quantity is physical quantity that ___________________ from the base

quantities.

List base quantities

and their S.I unit

3. Choose base quantities from the physical quantities given above and state their S.I

units.

No. Base Quantity S.I Unit

1.

2.

3.

4.

5.

PHYSICAL QUANTITY Pressure Time Current Length Area Temperature Weight Force Volume Work Energy Power Velocity Mass

S.I UNIT Second Newton Ampere Kelvin kilogram Pascal Joule m2 Watt m s-1 meter m3


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List some derived

quantities and their

S.I units

4. Write 5 derived quantities from physical quantities given in the box above (previous

page) and state their S.I units.

No. Derived Quantity S.I Unit

1.

2.

3.

4.

5.

Express quantities

using scientific

notation

5. Rewrite the values below in scientific notation (Standard notation)

No. Original value Scientific notation

1. 12 000 m

2. 3 000 000 000 s

3. 0.000 000 000 56 N

4. 0.000 78 J

5. 0.0034 A

Express quantities

using prefixes

6. Arrange the prefixes given below in ascending order. Then, state their multiple / sub-

multiple.

No. Prefix Multiple /

Sub-multiple

No. Prefix

Multiple /

Sub-multiple

1. 7.

2. 8.

3. 9.

4. 10.

5. 11.

6. 12.

Solving problem

involving

conversion of units

1. Rewrite the values below using the suitable prefix.

(i) 4.1 x 1012

m = __________ (vii) 3.8 x 102 K = __________

(ii) 9.3 x 101 s = __________ (viii) 1.7 x 10

9 W = __________

(iii) 0.5 x 10-3

J = __________ (ix) 4.1 x 103 C = __________

(iv) 11.2 x 10-2

N = __________ (x) 9.5 x 10-6

A = __________

(v) 5.9 x 106 V = __________ (xi) 8.6 x 10

-12 m = __________

(vi) 6.6 x 10-9

m = __________ (xii) 2.2 x 10-1

s = __________

PREFIXES Nano (n) kilo (k) pico (p) mega (M) centi (c) giga (G) deci (d) deca (da) tera (T)

hector (h) micro () milli (m)

MULTIPLE / SUB-MULTIPLE 103 109 10-2 101 10-12 106 10-6 102 10-1 10-9 10-3 1012


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2. Replaced the prefix in the values below with the correct multiple or sub-multiple.

(i) 4.1Tm = __________ (vii) 3.8 daK = __________

(ii) 9.3 ms = __________ (viii) 1.7 GW = __________

(iii) 0.5 kJ = __________ (ix) 4.1 hC = __________

(iv) 11.2 cN = __________ (x) 9.5 A = __________

(v) 5.9 MV = __________ (xi) 8.6 pm = __________

(vi) 6.6 dm = __________ (xii) 2.2 ns = __________

Check Yourself 1

1.

2.

3.

4.

5.

6.

7.

8.

9.

Which physical quantity has the correct S.I

unit?

Physical quantity S.I unit

A Temperature Celcius

B Time minute

C Mass Newton

D Length metre

Time, speed, density, and energy are ..............

quantities.

A base C vector

B scalar D derived

Which of the following shows the correct

relationship between the base quantities for

density?

A

B

C

D

Which of the following is not a base S.I unit?

A Gram C Ampere

B Kelvin D Meter

Which of the following physical quantities is

not a base quantity?

A Weight C Temperature

B Time D Electric current

A radio station airs its programmes by

transmitting waves at a frequency of

102.3 MHz. How much is this frequency, in

Hz?

A 1.023 x 102

B 1.023 x 105

C 1.023 x 106

D 1.023 x 108

Which of the following values is equal to 470

pF?

A 4.7 x 10-10

F

B 4.7 x 1011

F

C 4.7 x 10-7

F

D 4.7 x 102 F

Hamid cycles at a velocity of 3.1 km h-1

.

What is this velocity, in m s-1

?

A 0.09 C 1.16

B 0.86 D 11.61

Which measurement is the longest?

A 2.68 x 103 m

B 2.68 x 10-1

mm

C 2.68 x 103 cm

D 2.68 x 10-4

m


1-5

1.

3

10.

11.

UNDERSTANDING SCALAR AND VECTOR QUANTITIES

Define scalar and

vector quantities. 1. Read the statements below to make a generalisation on scalar quantity and vector

quantity. Then classify the physical quantities into scalar quantity and vector quantity

in the table below.

A Hasan walks with a velocity of 2 m s-1 due West.

B Husna runs with a speed of 5 m s-1.

C Sangeetha walks along a displacement of 40 m due North.

D Jason runs along a distance of 30 m.

E Chin Wen push the table downwards with a force of 30 N.

F Wen Dee has a mass of 40 kg.

Scalar Quantity Vector Quantity

(i) Scalar quantity is physical quantity that has _______________________.

(ii) Vector quantity is physical quantity that has _______________________ and

________________________.

Differentiate

between distance

and displacement.

2. Underline the correct physical quantity.

(i) (Distance / Displacement) is the total length travelled by an object.

(ii) (Distance / Displacement) is the shortest length measured between the initial

point and the final point.

Which of the following conversion of unit is

correct?

A 24 mm3 = 2.4 x 10

-6 m

3

B 300 mm3 = 3.0 x 10

-7 m

3

C 800 mm3 = 8.0 x 10

-2 m

3

D 1 000 mm3 = 1.0 x 10

-4 m

3

Which of the following frequencies is the

same as 106.8 MHz?

A 1.068 x 10-4

Hz

B 1.068 x 10-1

Hz

C 1.068 x 102 Hz

D 1.068 x 106 Hz

E 1.068 x 108 Hz


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EXAMPLE:

Check Yourself 2

1.

2.

3.

4.

A B

C

4 m

3 m

A boy walks from A to C through B.

(i) Distance of the boy = 4 m + 3 m = 7 m

(ii) Displacement of the boy = = 5 m

Diagram below shows the path travelled by a

car from P to S.

What is the displacement of the car?

A 5.0 km C 8.2 km

B 6.8 km D 9.0 km

Which quantity is a vector quantity?

A Area C Distance

B Length D Displacement

Which of the following is group of vector

quantities?

A Velocity, mass, displacement

B Speed, time, acceleration

C Force, velocity, displacement

D Area, temperature, momentum

Which of the following quantities is a vector

quantity?

A Energy C Force

B Power D Pressure

5 km

3 km

1 km

P Q

S R


1-7

U N D E R S T A N D I N G M E A S U R E M E N T S

Recognise

appropriate

instrument for

physical quantities

1. State the suitable measuring instrument for the physical quantities in the table below.

No. Physical Quantity Measuring Instrument

1. Temperature

2. Length

3. Time

4. Mass

5. Electric current

6. Voltage

7. Density

8. Atmospheric pressure

9. Pressure

10. Force

11. Volume

12. Diameter of tube

13. Diameter of wire

Measure physical

quantity using

vernier calliper.

2. Label the part of vernier calliper below.

MEASURING INSTRUMENT Metre rule Barometer Thermometer Lever balance Spring balance Hydrometer Measuring cylinder Bourdon gauge Ammeter Voltmeter Stopwatch Vernier calliper Micrometer screw gauge

PART OF VERNIER CALLIPER

Inner jaws Outer jaws Main scale Vernier scale

1.4

0 1 2 3 4 5 6


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3. Take the reading from a vernier calliper:

EXAMPLE:

4. Read the vernier calliper below.

(i) (ii)

(ii) (iv)

Measure physical

quantity using

micrometer screw

gauge.

5. Label the part of micrometer screw gauge below.

(i) Read the main scale.

Main scale reading = 0.70 cm

(ii) Read the vernier scale.

Vernier scale reading = 0.02 cm

(iii) Total up the readings.

Actual reading = 0.72 cm

3 4

0

Main scale = ....................

Vernier scale = ....................

Actual reading = ....................

2 3

0

Main scale = ....................

Vernier scale = ....................

Actual reading = ....................

8 9

0

Main scale = ....................

Vernier scale = ....................

Actual reading = ....................

0 1

Main scale = ....................

Vernier scale = ....................

Actual reading = ....................

PART OF MICROMETER SCREW GAUGE Anvil Spindle Sleeve Thimble Ratchet

0 1 2

0

(i) 0.70

cm

(ii) 0.02

cm


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6. Take the reading from a micrometer screw gauge.

EXAMPLE:

7. Read the micrometer screw gauge below:

(i) (ii)

(iii) (iv)

(i) Read the sleeve scale (main scale).

Sleeve scale reading = 3.00 mm

(ii) Read the thimble scale.

Thimble scale reading = 0.44 mm

(iii) Total up the readings.

Actual reading = 3.44 mm

0 50

40

(i) 3.00 mm

(ii) 0.44 mm

0 30

20

Sleeve scale = ....................

Thimble scale = ....................

Actual reading = ....................

0 20

10

Sleeve scale = ....................

Thimble scale = ....................

Actual reading = ....................

0

20

10

Sleeve scale = ....................

Thimble scale = ....................

Actual reading = ....................

0 60

50

Sleeve scale = ....................

Thimble scale = ....................

Actual reading = ....................


1-10

Explain sensitivity. 8. Table below shows readings from three instruments J, K, and L that are used in

measuring the mass of a Petri dish.

Instrument J Instrument K Instrument L

20 g 19.4 g 19.42 g

A piece of dried leaf of mass 0.05 g is then put in the Petri dish.

(i) Which instrument is able to detect the small change of the mass? [...............]

(ii) Which instrument is the most sensitive? [................]

(iii) Which instrument has the highest sensitivity? [................]

(iv) Sensitivity of instrument is the capability of the instrument to ...............................

..................................................................................................................................

(v) Which instrument gives reading in the most decimal place? [.................]

(vi) The ...................... the decimal place, the ........................... sensitivity of the

instrument.

Explain accuracy. 9. Table below shows readings from three instruments P, Q, and R that are used in

measuring the length of a wire. The actual length of the wire is 10.0 cm.

Instrument P Instrument Q Instrument R

10.1 cm 10.4 cm 9.6 cm

(i) Which instrument gives the closest reading to the actual length of the wire?

[...............]

(ii) Which instrument gives the most accurate reading? [...............]

(iii) Which instrument has the highest accuracy? [...............]

(iv) Accuracy of instrument is the capability of the instrument to ..................................

...................................................................................................................................

Explain

consistency

(Precision)

10. Table below shows four readings from three instruments X, Y, and Z that are used in

measuring the length of a wire. Each instrument repeats the measurement for four

times.

Instrument X 10.0 cm 10.1 cm 10.1 cm 10.0 cm

Instrument Y 10.1 cm 10.4 cm 10.2 cm 9.8 cm

Instrument Z 9.8 cm 9.6 cm 9.9 cm 9.5 cm

(i) Which instrument gives readings with the smallest deviation (difference)?

[...............]

(ii) Which instrument gives the most consistence readings? [...............]

(iii) Which instrument has the highest consistency? [...............]

(iv) Consistency of instrument is the capability of the instrument to .............................

...................................................................................................................................

(iv) Read the main scale.

Main scale reading = 0.70 cm

(v) Read the vernier scale.

Vernier scale reading = 0.02 cm

(vi) Total up the readings.

Actual reading = 0.72 cm


1-11

Explain type of

experimental error.

11. In an experiment, the readings of measurement taken may have slightly difference due

to some mistakes. The difference in the readings is called as .........................................

12. These errors can be caused by the change of environment, human factors or the

deficiency of measuring instrument.

13. Error that is caused by environment and human usually is (constant / changeable)*.

14. Error that is caused by the instrument is always (constant / changeable)*.

15. Type of Error:

Random Error Difference Systematic Error

Cause

Magnitude /

value

Example

Method to

reduce the

error

Check Yourself 3

1. 2.

.

A, B, C, and D shows the shooting marks on a

target. Which marks can explain the concept

of precision of a measurement?

A C

B D

A, B, C, and D show parts of four different

balance scales. Which balance is the most

sensitive?

A C

B D


1-12

3. 7.

4.

8.

5.

9.

6.

Diagram below shows the target board in a

game.

Which result is consistent but not accurate?

A C

B D

The diagram shows the scale of a micrometer

screw gauge.

What is the reading of the micrometer?

A 7.02 mm C 7.03 mm

B 7.52 mm D 7.58 mm

Target Target board

The diagram shows the scale of a vernier

calliper.

What is the reading of the vernier calliper?

A 2.16 cm C 1.86 cm

B 2.06 cm D 1.76 cm

Atmospheric pressure can be measured by

using

A hydrometer

B Bourdon gauge and manometer

C Bourdon gauge and mercury barometer

D manometer and mercury barometer

Table below shows the readings of the

thickness of a board which are taken by four

students.

Student Reading/cm

1 2 3 4

A 2.50 2.50 2.50 2.50

B 2.53 2.53 2.53 2.53

C 2.52 2.53 2.54 2.53

D 2.71 2.73 2.74 2.74

Each student made four measurements. If the

actual thickness of the board is 2.53 cm,

which of the students A, B, C, and D made

the measurements that are accurate but not

consistent?

Diagram (a) shows the reading of a vernier

calliper while its jaws are closed. Diagram (b)

shows the reading of the vernier calliper when

a metal sheet is placed between the jaws.

What is the thickness of the metal sheet?

A 0.46 cm C 0.38 cm

B 0.42 cm D 0.32 cm

(b) (a)

The diagrams show the scales on a pair of

vernier callipers and a metre rule.

Which comparison is correct about the

sensitivity of the vernier callipers and the

metre rule when measuring the thickness of a

wire?

Vernier callipers Metre rule

A Low sensitivity Low Sensitivity

B Low sensitivity High sensitivity

C High sensitivity Low sensitivity

D High sensitivity High sensitivity

Vernier calliper Metre rule


1-13

10. 14.

15.

11.

12.

13.

Four students, A, B, C, and D use a micrometer

screw gauge, a metre rule, and a vernier

calliper to measure the thickness of a board.

Which student records the reading correctly?

Micrometer Metre Vernier

screw rule/mm calliper/mm

gauge/mm

A 11.1 11 11.13

B 11.13 11.1 11.128

C 11.128 11.1 11.13

D 11.13 11 11.1

The diagram shows the scale of a micrometer

screw gauge.

What is the reading of the micrometer?

A 4.95 mm C 4.50 mm

B 4.55 mm D 4.45 mm

Which of the following statements is correct

about zero error?

A Can be reduced by determining average

reading.

B The magnitude of error increases when

the value of the reading increases.

C Exist either in positive or negative.

D The magnitude of error increases if the

range of scale is large.

Which of the following ways can reduce the

parallax error while taking reading of current

from an ammeter?

A Use a higher sensitivity ammeter.

B Repeat the measurement and calculate

the average reading.

C Take the reading using a magnifying

glass.

D Use ammeter that has plane mirror

below the pointer.

What is the function of the plane mirror under

the pointer in an ammeter?

A To increase the consistency of the

measurement.

B To increase the accuracy of the

measurement.

C To avoid parallax error.

D To prevent zero error.

Diagram below shows two types of ammeters,

X and Y, that can be used to measure electric

current.

(a) Which ammeter is more sensitive?

...................................................................

(b) State one reason for your answer above.

...................................................................

...................................................................

...................................................................


1-14

16.

18.

17.

Figure below shows the scale of an ammeter.

(a) Name the physical quantity measured by

the ammeter.

...................................................................

(b) What is the value of the smallest division

on the scale?

...................................................................

(c) State the function of the mirror located

under the scale.

...................................................................

...................................................................

Mirror

Figure below shows a vernier calliper used to

measure external diameter of a hollow

cylinder.

(b) Name the part labelled X.

...................................................................

(c) What is the function of X?

...................................................................

...................................................................

(a) The external diameters of the cylinder at

four different places are shown in the

table below.

External diameter/cm Relative

deviation/%

2.04 2.05 2.04 2.06 0.37

(i) Why is the external diameter

measured four times?

.............................................................

.............................................................

(ii) What is the purpose of calculating the

relative deviation?

.............................................................

.............................................................

.............................................................

Figure below shows the meniscus of oil in a

measuring cylinder. P, Q and R are three eye

positions while measuring the volume of the

oil.

(a) Which position of the eye is correct while

taking the reading of the volume of oil?

...................................................................

(b) Give one reason for the answer above.

...................................................................

...................................................................


1-15

19.

U N D E R S T A N D I N G S C I E N T I F I C I N V E S T I G A T I O N

Identify variables

in a given situation 1. Identify and state the variables that can be investigated from the situations below.

EXAMPLE:

The car moves faster when it is pushed harder.

Cause : pushed harder Manipulated variable : Force

Effect : moves faster Responding variable : Speed/Velocity/

Acceleration

No. Situation Manipulated

variable

Responding

variable

1. The temperature of smaller block rises

faster when it is heated.

2. The pendulum system with longer string

takes longer time to stop.

3. The loaded lorry is harder to stop than the

empty lorry.

4. The trolley that falls from the higher place

moves faster.

5. The spring becomes longer when it is

pulled harder.

A student is assigned to measure the thickness

of a metal sheet. The student is provided with

a vernier calliper.

(a) The student uses the vernier calliper to

measure the thickness of the metal sheet.

Figure (i) shows the scale of the vernier

calliper while the jaws are closed. Figure

(ii) shows the scale of the vernier calliper

when the metal sheet is put between the

jaws.

(ii)

(i)

(i) What is the zero error of the vernier

calliper?

.............................................................

(ii) Calculate the thickness of the metal

sheet.

Thickness = .................................

1.5


1-16

Making inference 2. Write inference from the given variables.

EXAMPLE:

Manipulated variable : Length Responding variable: Time

Inference : The length affects the time taken.

No. Manipulated

variable

Responding

variable Inference

1. Force Acceleration

2. Mass Temperature

3. Force Extension

4. Mass Time

5. Force Pressure

6. Area Pressure

7. Temperature Volume

Form hypothesis. 3. Write hypothesis from the given variables.

EXAMPLE:

Manipulated variable : Length Responding variable: Time

Hypothesis : The longer the length, the longer the time taken.

No. Manipulated

variable

Responding

variable Hypothesis

1. Force Acceleration

2. Mass Temperature

3. Force Extension

4. Mass Time

5. Force Pressure

6. Area Pressure

7. Temperature Volume


1-17

Analyse the data. 4. Data obtained from an experiment can be analysed by plotting a line graph.

Manipulated variable is on the x-axis, and responding variable is on the y-axis.

The variables must be stated together with the correct unit.

EXAMPLE:

Manipulated variable : Mass

Responding variable : Time

5. Sketch a graph to analyse the following variables:

(i) Manipulated variable : Force (ii) Manipulated variable : Mass

Responding variable : Acceleration

Responding variable :

Temperature

(iii) Manipulated variable : Force (iv) Manipulated variable : Mass

Responding variable : Extension Responding variable : Time

Mass/kg

Time/min


1-18

(v) Manipulated variable : Force (vi) Manipulated variable : Area

Responding variable : Pressure Responding variable : Pressure

Interpret data to

draw a conclusion.

6. The conclusion of an experiment is made based on the line graph obtained.

EXAMPLE:

Conclusion: Conclusion:

The time is directly proportional

to the mass.

The pressure is inversely proportional

to the area.

Conclusion:

The temperature is linearly

increasing with the time.

Mass/kg

Time/min

Pressure/Pa

m-2

Time/min

Temperature/C


1-19

Interpret data to

draw a conclusion.

7. Write a conclusion based on the line graphs below:

(i) (ii)


........................................................

........................................................

.......................................................

.............................................................

.............................................................

.............................................................

(iii) (iv)


........................................................

........................................................

.......................................................

.............................................................

.............................................................

.............................................................

Length/cm

Period2/s

2 Temperature/C

kg

-2

Pressure/kPa Force/N

Volume/m3

Extension/cm


1-20

A

C

B

D

Check Yourself 4

1.

.

4.

2.

5.

3.

Which of the following graphs obeys the

equation F = kx, where k is a constant?

A C

B D

Table below shows the results of an experiment

to investigate between load and extension when

a spring is stretched.

Load, F/N 100 150 200 250 300

Extension,

x/cm 1.0 1.5 2.0 2.5 3.0

The original length of the spring is l0 = 15.0 cm.

What is the manipulated variable?

A Load, F

B Extension, x

C Original length of the spring, l0

D Material used to make the spring

The graph shows the relationship between v

and t.

The relationship between v and t is

represented by the equation

Diagram below shows an investigation about

the stretching of a spring. Babies of different

masses are supported by identical springs.

Which of the following variables are correct?

Manipulated

variable

Responding

variable

Constant

variable

A Mass of the

baby

Length of

the spring

Diameter of

the spring

B Length of

the spring

Mass of the

baby

Diameter of

the spring

C Diameter of

the spring

Length of

the spring

Mass of the

baby

D Mass of the

baby

Diameter of

the spring

Length of

the spring

The graph shows the relationship between

physical quantities P and Q.

Which statements about the graph is correct?

A If Q = 1, then P = 2.

B The gradient of the graph is 1.

C P is directly proportional to Q.

D The equation of the graph is P = 1 + 3Q

1.0 understanding physics

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