1. Gravitational Potential and Kinetic Energy

2. Gravitational Potential Energy
Energy an object has due to it’s position above a reference level

3. Gravitational Potential Energy
Where:
Eg – Gravitational Potential Energy (J)
h – Height above reference level (m)
g – Acceleration due to gravity
g=9.81m/s2
m – Mass of the object (kg)

4. Kinetic Energy
Energy due to the motion of an object

5. Kinetic Energy Where: Ek – Kinetic Energy (J) v – Speed (m/s)
m – Mass of the object (kg)

6. Wrecking Ball Example Kinetic Energy Potential Energy Potential Energy
Reference Level
Kinetic Energy
Potential Energy
Potential Energy

7. The wrecking ball is constantly converting energy from potential to kinetic and back
In an ideal situation, the height will stay the same (zero energy will be lost)

8. Example 1
Calculate the potential energy of Mr. Simnett (mass is 100kg) when he jumps 1.0m above the ground.

9. Example 2
Calculate the kinetic energy of Mr. Simnett when he is running at 1.5 m/s (m=100kg).

10. Work
Pg 142 # 1,3,4
Pg 143 # 7-10