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)
    • 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.

--Richard Lou