1. Lesson 2 Energy Transfers and Transformations
Using Energy and Heat
Lesson 2
Energy Transfers and Transformations

2. Law of Conservation of Energy
Energy CAN be transformed or transferred
Energy CANNOT be created.
Example: Chemical energy from a battery is transformed to electric energy which is then transformed to radiant (light) energy and thermal (heat) energy
The amount of radiant energy that shines out of the flashlight cannot be greater than the chemical energy from the battery.

3. Law of Conservation of Energy

4. Energy Transfer vs. Energy Transformation
Energy Transfer – Energy moves without changing form.
Thermal energy from the heater is transferred to you as thermal energy
Energy Transformation – Energy changes form as it moves.
Conversion of chemical energy from the food you eat to mechanical energy (when your body moves).
Any time there is an energy transformation or transfer, some energy is transformed to thermal energy

5. Work and Systems
Work – the transfer of energy that occurs when a force makes an object move in the direction of the force.
Only when force is acting on it.
Open System – A system that exchanges matter or energy with the surrounding environment.
Closed System – A system that does not exchange matter or energy with the environment.
Closed systems do not exist.

6. Renewable and Non-renewable Energy
Renewable – can be replaced as fast (or faster) as it is used.
Example – Wind, solar, hydroelectric, geothermal
Non-renewable – cannot be replaced as fast as it is used.
Example – Fossil fuels (petroleum, natural gas, propane, and coal)
Example – Nuclear energy plants (fission of uranium atoms)
Most of the energy in the US comes from non-renewable resources