- 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.
