1. Animation Examples of Kinetic and Potential Energy

2. Roller Coaster
Energy is conserved throughout the ride and is merely being changed from K.E. to P.E. and vice versa
Notice that the Total Mechanical Energy remains constant during the animation

3. Pendulum Example
At the highest point on each side, the Kinetic Energy is equal to zero
The Energy is being converted back and forth from K.E. to P.E.

4. Conservation of energy
Section 5-3
Conservation of energy

5. Conserved Quantities The mass of the light bulb is constant
This is true if the light bulb is whole or in pieces
We will be applying this same principle to energy

6. Mechanical Energy
Definition: the sum of kinetic energy and all forms of potential energy
ME= KE + ∑PE
Mechanical energy is often conserved

7. Energy Classification

8. Conservation of Mechanical Energy
In the absence of friction, the total mechanical energy remains the same
This is called the conservation of mechanical energy
MEi = MEf
Initial mechanical energy = Final mechanical energy

9. ME cont. Energy conservation occurs even when acceleration varies
Example: The Roller Coaster Animation
Exception to the rule: Mechanical energy is not conserved in the presence of friction
Sanding block in Figure 5-12