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

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. C o )  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 = mc  T  m-mass in grams or kilograms  Q- thermal energy in Joules  c-specific heat in J/kg. C o or J/g. C o   T-change in temperature in C o

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

22.   l=l  T   l-change in length  l-original length   coefficient of linear expansion   T-change in temperature

23. Change in Volume  Liquids expand 100 times more than solids   V=V  T

24.   V-change in volume  V-original volume   coefficient of volume expansion   T-change in temperature