What is Potential Energy

Potential energy is energy which results from position or configuration. An object may have the capacity for doing work as a result of its position in a gravitational field (gravitational potential energy), an electric field (electric potential energy), or a magnetic field (magnetic potential energy). It may have elastic potential energy as a result of a stretched spring or other elastic deformation. Mechanical potential energy is gravitational potential energy and elastic potential.

 Definition provided by HyperPhysics

Gravitation Potential Energy 

What is Gravitational potential energy

      Gravitational potential energy is energy an object possesses because of its position in a gravitational field. The most common use of gravitational potential energy is for an object near the surface of the Earth where the gravitational acceleration can be assumed to be constant at about 9.8 m/s2.  The potential energy at a height h above that point is equal to the work which would be required to lift the object to that height. Since the force required to lift it is equal to its weight, it follows that the gravitational potential energy is equal to its weight times the height to which it is lifted.

Hints when solving problems with gravitational potential energy

      Since the zero of gravitational potential energy can be chosen at any point, so setting were this point is zero, it can make the solving these problems easier.

Definition provided by HyperPhysics

Example problem 

 A box has a mass of 5.8kg. The box is lifted from the garage floor and placed on a shelf. If the box gains 145J of Potential Energy (PE),how high is the shelf?


Use PE = mgh 

 PE = potential energy (Joules)

m = mass of box (kg)

g = gravitational field strength (N/kg)

h = difference in height (m)

PE = mgh 

(147 J) = (5.8 kg)(9.8 m/s/s) h 

(147 J) / (5.8 kg)(9.8 m/s/s) = h 

h = 2.5 m 

Example provided by Mr Mackenzie