Copyright © Michael Richmond. This work is licensed under a Creative Commons License.

Gravitational Potential Energy, and Conservation of Energy

• There are many different forms of energy. It is possible to convert energy from one form to another.
• Gravitational potential energy (GPE) is associated with an object's mass and its position. It is equal to the work one must do to lift an object some distance against a gravitational force.
```                    GPE  =  (mass) * g * (height)
```
• If an object falls, it gives up its gravitational potential energy. The gravitational force does work on it, and speeds it up. Its GPE is converted into kinetic energy.

• Mechanical Energy is defined as the sum of the kinetic and gravitational potential energy:
```                    E    =    KE      +    GPE

= 0.5 m*v^2  +   m*g*H
```
• In the absence of friction, or any external force, the mechanical energy in a system is conserved.
```                 E(initial)            =         E(final)

KE(initial) + GPE(initial)  =  KE(final) + GPE(final)
```
• A conservative force is one which does the same amount of work on an object that moves from point A to point B, no matter what path it takes along the way.
• Gravity is a conservative force.

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Copyright © Michael Richmond. This work is licensed under a Creative Commons License.