1. Mechanical Energy, Me (Units of joules (J))
Kinetic Energy
Potential
Energy

2. Potential Energy, Pe (Units of joules (J))
The energy of possible (potential) motion! (Also called stored energy).

3. Potential Energy, Pe (Units of joules (J))
Elastic
Chemical
Gravitational

4. Chemical Potential Energy, PE (Units of joules (J))
The energy stored within chemical bonds.

5. Elastic/Spring PE, PEs (Units of joules (J))
The energy due to compression or expansion of an elastic object.

6. Elastic/Spring PE, PEs (Units of joules (J))
PEs = ½kx2
Spring stretch length in (m)
Spring force constant (the toughness of the spring) in (N/m)

7. Gravitational PE, PEg (Units of joules (J))
The energy of position!

8. Gravitational Potential Energy, PEg (Units of joules (J))
Which goat has the most potential energy?

9. Gravitational Potential Energy, PEg (Units of joules (J))
PEg = mgh
Height off the ground (in m)
Mass (in kg)
+ 9.8 m/s2
*We use positive gravity because of our frame of reference for the problem so that PEg is a positive measurement!

10. Pes Example
A spring is compressed 0.3 m and held in place. It has a spring constant of 5 N/m. How much PE does it have?
G: x = 0.3m
k = 5 N/m
U: PE = ?
E: PE = ½ k2
S: PE = J

11. Complete #3 on the GP with your partner!
Potential Energy
Guided Practice!
Complete #3 on the GP with your partner!

12. Peg Example
A 10kg goat is in a tree, 15m above the ground. How much potential energy does it have?
G: m = 10 kg
h = 15m
U: PE = ?
E: PE = mgh = 10*9.8*15
S: PE = 1470 J

13. Complete #4 on the GP with your partner!
Potential Energy
Guided Practice!
Complete #4 on the GP with your partner!