1. Thermal Energy

2. Temperature
Measures the “hotness” (higher temperatures) or “coldness” (lower temperatures)
Gives very little information on the energy that the material contains.

3. Temperature  Heat
Some equate temperature to heat
Temperature and Heat are not the same

4. Temperature All matter is made up of tiny particles
These tiny particles are constantly moving

5. All moving things have kinetic energy
The faster the particles move the more KE
The temperature is a measure of the average Kinetic Energy

6. Thermal Energy Place a ice-cold spoon on ice cream. What happens?
Place a hot spoon on ice cream. What happens?

7. Place two hot spoons on ice cream. How is it different?
Pour hot water on the ice cream. How is this different from the spoon?

8. Thermal Energy
Thermal energy is the total amount of kinetic and potential energy of a material
Kinetic energy determined by the speed of the moving particles

9. Potential energy determined by the distance between the particles

10. Thermal Energy & Temperature
They are related
As temperature increase so does the kinetic energy and the potential energy of the particles

11. Thermal Energy
Depends upon temperature
Mass of material
Type of material

12. Heat
The transfer of thermal energy

13. Heat
Heat is the energy that flows from an object of higher temperature to an object with lower temperature
Heat is measured in units of Joules

14. So… Does an ice cube in warm water cause the water to cool down
Or does the warm water cause the ice cube to melt?

15. Specific Heat
Why is the air around the swimming pool warmer than the water even if they have both been exposed to the sun the same amount of time?

16. Different materials need different amounts of heat to change the temperature the same amount.
Copper pot –vs- water

17. Specific Heat is the amount of heat necessary to raise the temperature of one kilogram of a material one degree Celsius

18. Units (J/kg.Co)
Specific heat of water very high
Advantages?
Disadvantages?

19. Measuring Specific Heat
Cannot measure the amount of heat energy transferred
Can only measure the resultant change in thermal energy

20. Q = mcDT
m-mass in grams or kilograms
Q- thermal energy in Joules
c-specific heat in J/kg.Co or J/g.Co
DT-change in temperature in Co

21. Change in Length When temperature is increased objects expand
Sidewalks, siding on houses, railroad tracks, bridges, etc…

22. Dl=laDT
Dl-change in length
l-original length
a-coefficient of linear expansion
DT-change in temperature

23. Change in Volume
Liquids expand 100 times more than solids
DV=VbDT

24. DV-change in volume
V-original volume
b-coefficient of volume expansion
DT-change in temperature