Experiment: Gravity Potential Energy = Force x Distance

To show you how this works, study the following example.

If the washers had a mass of 2 grams, and since the force due to gravity in the metric system is 9.8 m/sec2, the weight would be:

W = mass (kg) x gravity

W = 0.002 kg x 9.8 = 0.0196 Newton's. The Newton (N) is the measure of force (or weight here) in the metric system.

The next phase of the computation is to determine the difference in potential energy between where the washers originally started from and the energy of the new position. If the washers were originally 1 meter from the floor or desktop, and the magnet raised them 1 centimeter, the difference in distance raised will be 1 cm, or 0.01 m. Therefore, the potential energy change will be:

Force x Distance = Potential Energy

(0.0196 N) x (0.01 m) = 0.000196 Nm (or Joules)

The magnet is changing the potential energy of the washers by 0.000196 J, or in scientific notation:
1.96 x 10-4 J.