Gravitational Potential Energy in a Non-Uniform Field (DP IB Physics)

Gravitational Potential Energy in a Non-Uniform Field

• In a radial field, gravitational potential energy (GPE) describes the energy an object possesses due to its position in a gravitational field

• The gravitational potential energy of a system is defined as:

  The work done to assemble the system from infinite separation of the components of the system

• Similarly, the gravitational potential energy of a point mass is defined as:

  The work done in bringing a mass from infinity to a point

Near the Earth's Surface

• The gravitational potential energy near the Earth's surface is equal to

• The GPE on the surface of the Earth is taken to be zero

  • This means work is done to lift the object

• This equation can only be used for objects that are near the Earth's surface

  • This is because, near Earth's surface, the gravitational field is approximated to be uniform

  • Far away from the Earth's surface, the gravitational field is radial because the Earth is a sphere