1. Chapter 6: Thermal Energy

2. Temperature and Heat
Chapter 6 Section 1 Page 158

3. At the end of all this, you should be able to…
Define temperature
Explain how thermal energy depends on temperature
Explain how thermal energy and heat are related
Calculate the change in thermal energy

4. Review Vocabulary Recall that last week we defined:
Kinetic Energy - the energy an object has due to its motion.
Thermal Energy - the vibration or movement of atoms and molecules.

5. Temperature Matter in Motion:
All matter is made up of atoms and molecules and they are ALWAYS in constant, random motion.
If they are moving, they have kinetic energy.
Temperature - measure of the average kinetic energy of all the particles in an object.

6. Temperature
Hot tea has a higher temperature than iced tea because the particles in the hot tea are moving faster than the particles in the iced tea.

7. Hot tea vs. Cold Tea https://www.youtube.com/watch?v=ZBuXwPaWgh8
Food dye for the fun

8. Heat
How can you tell if someone was sitting a chair before you?

9. Heat
You know if someone was in the seat before you because it feels warm. It feels warm because thermal energy was transferred from a person to the chair and increased the temperature of the chair.
Heat does NOT mean hot!
Heat - thermal energy that flows from a warmer material to a cooler material.

10. Heat If heat is transferred into an object it gets warmer.
If heat is removed from an object it gets cooler.
The kettle is getting warmer because heat is being transferred into it.

11. Specific Heat Not all things warm up or cool down at the same rate.
Specific Heat - amount of thermal energy needed to raise the temperature of 1 kg of a material 1oC.
When you place a pot of water on a stove, which feels hot quicker, the pot or the water?

12. Specific Heat The pot gets hot much quicker than the water does.
This is because water takes 10x as much thermal energy as metal does to heat up.
Every material has it’s own unique specific heat.

13. Summary
The temperature of an object depends on the kinetic energy of its atoms or molecules.
Heat is thermal energy that is transferred into or from an object.
If heat is transferred to an object it gets warmer, if it is removed from an object it gets cooler.
Specific heat tells you how easily a material can be heated up.