Week #1 Quarter 3 (1/3-1/17) (calendar site) Monday, 1/13 Pick Up: Handouts Have out: Temperature and Heat Outline Notes Activities/Assignments: 1. Collect Signatures 2. Check for Notebooks 3. Temperature Scales Today in I.S.… I.S. Learning Goal: Differentiate between the different temperature scales (Celsius, Fahrenheit, Kelvin) Homework:
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Week #1 Quarter 3 (1/3-1/17) (calendar site)(calendar site) Monday, 1/13 Pick Up: Handouts Have out: Temperature and Heat Outline Notes Pick Up: Handouts.
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Now you try! Complete the worksheet on “Comparing Fahrenheit, Celsius, and Kelvin”
APES Learning Goal:Compare and contrast thermal expansion and contraction
APES Learning Goal:Compare and contrast thermal expansion and contraction
Combining Different TemperaturesOverview
For this activity you will mix different amounts of hot and cold water.
• Materials: 3 - 250 mL beakers 2 - 100 mL graduated cylinder three Celsius thermometers hot and cold water
• Procedures:1. Label the three beakers (H, C, M).2. Using the graduated cylinder, measure the amount of cold water
specified by the data table and pour it into the beaker labeled “C.” Measure and record the temperature.
3. Using the graduated cylinder, measure the amount of hot water specified by the table and pour it into the beaker labeled “H.” Measure and record the temperature.
4. Predict what the temperature will be after combining the beakers.5. Pour the hot and cold water into the beaker labeled “M.” Measure and
record the water temperature.6. Repeat steps 2-5 for the remaining mixtures specified by the data
table.
Data Table
Mixture Hot WaterTemperatur
e (0C)
Cold WaterTemperatur
e (0C)
Predicted Mixed
Temperature (0C)
Actual Mixed
Temperature (0C)
100 mL hot;100 mL cold
50 mL hot;150 mL cold
150 mL hot;50 mL cold
Questions1. How does the temperature of the different mixtures compare
to the original temperatures of the water?2. For which mixture did your prediction come closest?3. For which mixture was your prediction farthest off?4. Could the temperature of the mixture (hot and cold) ever
reach the temperature of the hot or cold water? Explain your reasoning.
5. Although the hot water was the same temperature in each beaker, the impact observed when it was combined with the cold water varied. Why did they all have a different effect?
6. What factors could have impacted the accuracy of your data?
7. What did you learn about mixing temperatures from this activity?
8. What would you predict the temperature to be if 200 mL of hot water (≈1000C) is mixed with 50 mL of cold water (≈00C) ? Explain your reasoning.
Activities/Assignments:1. Thermal Expansion and contraction
notes2. Specific heat notes3. Conductors and Insulators Notes4. Three Types of Heat Transfer Notes
Today in I.S.…
I.S. Learning Goal: Compare and contrast thermal expansion and
contraction Explain specific heat and its connection to mass Compare and contrast conductors and insulators Compare and contrast the three types of heat
transfer (conduction, convection, radiation) Homework:
and ContractionTry to apply and/or explain the concepts of thermal expansion and contraction as they pertain to the following examples.
o expansion joints in bridges or sidewalkso thermometerso hard to open jar lido railroad tracks and train derailmentso telephone/power lineso potholes o objects filled with gas (tire, balloon, athletic ball, etc.)
What are some personal examples or experiences with thermal expansion and
APES Learning Goal:Compare and contrast thermal expansion and contraction
APES Learning Goal: Explain specific heat and its connection to mass
Heat• flow or transfer of energy from an object at a higher
temperature to an object at a lower temperature until thermal equilibrium is reached
• matter does not have heat it has thermal energy• typically expressed in units of joules (J) and calories
(cal)o Calories is really a kilocalorie and represents food
energyo 4.187 joules = 1 calorie
• scientists believed that heat was an invisible, weightless fluid capable of flowing calorico Count Rumford (Benjamin Thompson) challenged the
idea of caloric when he discovered that heat was being produced when holes were drilled into cannon barrels
• 3 types of heat transfer: conduction, convection, radiation
Why does an ice cube feel cold while a paper cup filled with coffee feels
hot?
Specific Heat Capacity• the amount of energy needed to change the temperature
of 1 kg of a substance by 10C• how easily substances change temperatures• increases as the size of the particles that make up the
substance increase• the higher the value the more energy and the longer it
takes to heat up or cool down• i.e. – with a specific heat of 1.00 cal/g0C, water (0.93 cal/g0C
for ocean water) will take longer to heat up and cool down compared to copper which has a specific heat value of 0.09 cal/g0C
• can be used to help calculate heat lost or gained by a substanceo formula: MC∆T
Explain how/why bodies of water in our area are warmer
towards the end of the summer compared to the beginning.
Table of Specific Heat Values
Substance Specific Heat(cal/g0C)
Specific Heat(J/kg0C)
Air 0.25 1,046
Aluminum 0.22 899
Copper 0.09 387
Glass 0.20 837
Ice (-200C to 00C) 0.50 2,090
Iron 0.11 448
Mercury 0.03 138
Ocean Water 0.93 3,894
Water 1.00 4,187
Wood 0.42 176
APES Learning Goal: Explain specific heat and its connection to mass
APES Learning Goal:Compare and contrast conductors and insulators
Conduction• transfer of thermal energy through a
substance, or from one substance to another by direct contact of particles
• takes place in solids, liquids, and gases, but takes place best in solids because the particles of a solid are in direct contact with each other Unfortunately for someone, after
being touched, the heat will transfer from the iron to the hand. What are some other real-life examples where heat is transferred by conduction?
Conductors and Insulators
• Conductorso substances that
conduct thermal energy well
o particles are close together
o different metals are common conductors
• Insulatorso substances that do
not conduct thermal energy well they delay heat transfer
o particles are far apart
o different plastics are common insulators
What are some common conductors and insulators?
APES Learning Goal:Compare and contrast conductors and insulators
APES Learning Goal:Compare and contrast the three types of heat transfer (conduction, convection, radiation)
Convection• transfer of thermal energy through fluids
(liquids or gases) by means of up and down movements called convection currentso the circular motion of liquids or gases due to
density differences that result from temperature differences
Sea and land breezes result from uneven heating of the
Earth’s and the resulting convection currents. Explain
how this happens.
As the air gets heated by the flame, the particles move faster and spread out. This increases the volume of the
air inside the balloon, which lowers the density. This decrease in density
causes the balloon to rise.
Radiation• transfer of thermal (radiant) energy as
electromagnetic waves, such as visible light or infrared waves
• energy can be transferred through matter or empty space
• darker objects absorb more radiant energy than lighter objects
Notice how the visible light from the sun travels through space and heats the Earth.
Now you try ! Complete the worksheet on “Heat Transfer -Conduct ion, Convect ion, R adiat ion”
Temperature vs. Heat vs. Thermal
Energy
Temperature Thermal Energy
Heat
a measure the average kinetic energy of all the
particles in an object
the total energy of the particles in a
substance
the transfer of energy between
objects that are at different
temperatures
expressed in degrees Fahrenheit,
Celsius, or Kelvin
expressed in joules expressed in joules or calories
does not vary with the mass of a
substance
varies with the mass and temperature of
a substance
varies with the mass, specific heat
capacity, and temperature change
of a substance
Calculating Heat – Sample Problem
• How many joules are needed to raise the temperature of 100 kilograms of copper from 10 C to 100 C? The specific heat of copper is 387 J/kg·C.
Q = mc∆T
Heat =(100 kg)
Heat = 3,483,000 J
(90 C)
Take thedifference
between 100Cand 1000C
heat massspecificheat
change intemperature
387 J kg·C
APES Learning Goal:Compare and contrast the three types of heat transfer (conduction, convection, radiation)