1. April 30, 2010 Bring up your lab from yesterday!
A car has a mass of 10,000 kg. What is the KE of the car moving at 6 m/s?
What is the PE of that car stopped at the top of a 20 m hill?
What is the KE of the car stopped at the top of the hill?
If the car travels to 10 m, what is the KE of that car?

2. Energy Transformation
Energy Transfer
Energy moves from one object to different object
ex. Boiling water on stove
Energy Transformation
Energy changes from one form to another (still in same object!)
Ex. Light  heat

3. Q: What is the Law of Conservation of Energy
This is similar to the Law of Conservation of Mass/Matter!
The Law of Conservation of Energy says energy cannot be created or destroyed, but it can be transformed from one form to another.

4. Forms of energy:
Mechanical (includes elastic: springs, rubber bands, etc)
Light (fits into electromagnetic)
Sound (fits into mechanical)
Heat (friction)
Electrical (fits into electromagnetic)
Chemical
Nuclear

5. Examples of Energy Transformations:
Ex) Rubbing your hands together
Mechanical energy Heat energy

6. Examples of Energy Transformations:
Ex) On a roller coaster ride all of the energy for the entire ride comes from the conveyer belt at the beginning of the ride.
This energy is then stored as GPE at the top of the first hill.
As the coaster travels down the first hill, the GPE is converted to KE.
In the real world, a small amount of this energy is lost as heat to the wheels and vibrations that produce the roaring sound!

7. ADD THIS TO YOUR NOTES KE + PE = Total Energy
At the top of a hill, KE = 0 J. All energy is PE.
Halfway down the hill, 50% of energy is KE and 50% is PE
Height was cut in half. Height is directly proportional to PE. So PE is cut in half.
At the bottom, all the energy that was PE at the beginning has been changed into KE. (so now PE = 0 and all energy is KE)