1. Energy

2. Energy & Work Closely related Energy: ability to do work Work: transfer of energy Both measured in Joules

3. Energy Types 1.Kinetic Energy: Energy in motion 2.Potential Energy: Stored energy (not moving) depends on position or condition of object

4. Examples of KE

5. Examples of PE Firecracker Boulder on top of cliff battery

6. Calculating KE KE = ½ mv 2 m = mass v = velocity Which increases kinetic energy more: doubling the mass or doubling the velocity?

7. Gravitational PE PE that depends on object’s height, and weight G.P.E. = mgh m = mass g = 9.8 m/s 2 h= height. Which will have greater GPE: a rock on a 3 story ledge or a rock on a 20 story ledge?

8. Mechanical Energy PE Converts to KE and vice versa Mechanical Energy = KE + PE –Total energy Skier Roller Coaster Dart

9. Energy conversions Law of conservation of energy: Energy cannot be created or destroyed, only converted from one form to another