1. Energy & Transformations
THERMAL ENERGY & HEAT

2. Heat vs. Temperature
Thermal Energy: The total kinetic and potential energy of molecules of a substance.
Heat: A measure of the energy transferred from a warm body to a cooler one.
Temperature: A measure of the average kinetic energy of the atoms or molecules of a substance.
Heat transfers naturally from an area of high temperature to low temperature.
Higher temperature = higher thermal energy

3. Example 1 A 850C 250 mL cup of water is poured into 2L of milk at 250C
Compare the kinetic energies of the molecules of each substance.
Compare the thermal energies of both substance.
When would heat stop transferring from the water into the milk?

4. Methods of Heat Transfer
Conduction: The transfer of heat by direct contact.
Convection: The transfer of heat through a fluid.
Radiation: The transfer of heat by means of electromagnetic waves (EM).

5. Example #2
Determine the type of heat transfer in each situation. In which direction does heat transfer?
An ice pack is placed on a twisted ankle.
A whole turkey is cooked inside of an oven for dinner.
A microwave oven cooks a delicious microwave lunch.

6. Example #3
A ball is dropped vertically from a height of 3m. It rebounds to a height of 2m.
Draw the energy transformation equation when it hits the ground and when it has rebounded to the max height.
Does this violate the law of conservation of energy?