Ch. 2Ch. 2Sec. 2 Sec. 2 Heat Heat

TransferTransfer

measuring temperature

• total energy of motion in the molecules of a substance

temperature• average amount of energy of motion

of each molecule of a substance

– measure of hot or cold

– measured w/ thermometer

Temperature • measured in units called degrees

Temp. of water Celsius scale Fahrenheit scale

100o C 212o F

0o C 32o F

•energy transferred from hotter object cooler object

heat

How Heat is Transferred:

1. radiation• direct transfer of energy• transfers heat from Sun to Earth

2. conduction• direct transfer of heat from one substance to another substance that is touching

3. convection• transfer of heat by movement of a fluid

• causes most heating of troposphere

Convection

•Problem: Does altitude affect air temperature?• Research: measure in C or F, w/ thermometer,

freezing & boiling point of water, thermal energy• Hypothesis: If a thermometer is placed on the ground,

then it will have a higher temperature than a thermometer in a tree because most sunlight is absorbed by the ground. Therefore, the lower the altitude the higher the temperature.

• Procedure: 1. Place 3 thermometers in different areas:• On the ground• On the bushes• On top of the playground2. Make sure all the thermometers are in the sun3. Measure the temperatures of each every 5 minutes.4. Find the average temperature of each thermometer.

Location 1 xxxxx

(on ground)

Location 2

(on x bushes)

Location 3

(on top of playground)

Time 1:15 pm- C 1:15 pm- C 1:15 pm- C

5 min.

10 min.

15 min.Average of 3 times

•Problem: Does altitude affect air temperature?