Difference Between Gravitational Potential Energy and Potential Energy

Gravitational Potential Energy vs Potential Energy

Gravitational potential energy and potential energy are two important concepts in mechanics and statics of physical bodies. This article briefly explains the two concepts first, and then compares the similarities and differences between them.

What is Gravitational Potential Energy?

To understand gravitational potential energy, background knowledge in gravitational fields is required. Gravity is the force that occurs due to any mass. Mass is the necessary and sufficient condition for gravity. There is a gravitational field defined around any mass. Take masses m₁ and m₂ placed in a distance r from one another. The gravitational force between these two masses is G.m₁.m₂ / r², where G is the universal gravitational constant. Since negative masses are not present, the gravitational force is always attractive. There are no repulsive gravitational forces. It must be noted that gravitational forces are also mutual. That means the force m₁ exerts on m₂ is equal and opposite to the force m₂ is exerting on m₁. The gravitational potential at a point is defined as the amount of work done on a unit mass when bringing it from infinity to the given point. Since the gravitational potential at infinity is zero and the amount of work to be done is negative, the gravitational potential is always negative. The gravitational potential energy of an object is defined as the work done on the object when the object is taken from infinity to the said point. This is also equal to the product of gravitational potential and the mass of the object. Since the mass of the object is always positive and the gravitational potential of any point is negative, the gravitational potential energy of any object is also negative.

What is Potential Energy?

Potential energy of an object is the energy of an object due to the placing of the object. Potential energy can have many forms. Gravitational potential energy is the potential energy of an object having a mass acquires due to the placement of the object. Electrical potential energy, which is also known as electrostatic potential energy, is the energy of an object having a charge it experiences due to the placing. The magnetic potential energy, which is also known as electrodynamic potential energy, is the energy experienced by an object having a magnetic field due to the placing. Gravitational potential energy can only be negative. There are other forms of potential energy such as nuclear potential energy, chemical potential energy and elastic potential energy. Potential energy can occur due to contact forces. This type of potential energy is experienced in elastic potential energy. Most of the other potential energies occur due to fields.