3.5 Calculating Energy

Work & Energy

Gravitational Potential Energy

To have potential energy, an object must be part of a system that can apply force to the object.

We may not think of it, but the Earth is part of a system creating potential energy for all masses on it's surface. 

Thus, the most common potential energy that we experience is gravitational potential energy.

We can calculate the gravitational potential energy of an object using:

begin mathsize 28px style E subscript p space equals space m g h end style
Where,
  • m = the mass of the object (in kg)
  • g = gravitational constant for the surface of Earth (in m/s2)
  • Ep = potential energy (in Joules)
  • note that "mg" together make the force of gravity (in Newtons)