Explain that a change in gravitational potential energy is related to work done.
- Potential Energy is energy that is "stored" which can be converted into other forms of energy.
- Gravitational potential energy (GPE) is the energy of a mass due to its position within a gravitational field.
- $e.g.$ If a ball is placed atop a cliff, it will have the stored energy.
- Keep in mind that GPE is equivalent to work done in moving something to a point.
- W = Fs:
- W is work done(J)
- F is force applied(N)
- s is displacement(m)
- W = Fs:
- From this equation, we can say that, if we take the Earth's surface as the point of 0 GPE, we can find GPE using:
-
- GPE = mgh
- m is the mass of the object(kg)
- g is the gravitational acceleration of Earth($9.8 ms^{-2}$)
- h is the vertical distance between the object and the Earth's surface(m)
- Note that this equation can work with other planets as well, obviously switching the value of $9.8 ms^{-2}$ to whatever the other planet's gravitational acceleration is.
- GPE = mgh
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--Richard Lou
page revision: 1, last edited: 29 Dec 2010 07:36