Gravitational potential energy

Definition

Gravitational potential energy is the energy an object possesses due to its position in a gravitational field. It is often calculated using the formula $U = mgh$, where $m$ is mass, $g$ is gravitational acceleration, and $h$ is height.

5 Must Know Facts For Your Next Test

1. Gravitational potential energy depends on an object's mass, the height above a reference point, and the acceleration due to gravity.
2. The formula for calculating gravitational potential energy is $U = mgh$.
3. Gravitational potential energy is a scalar quantity and has units of joules (J).
4. In a closed system with no non-conservative forces, gravitational potential energy can convert into kinetic energy and vice versa, but the total mechanical energy remains constant.
5. When dealing with planetary bodies or objects at significant distances from Earth, gravitational potential energy may be calculated using $U = -\frac{GMm}{r}$, where $G$ is the gravitational constant, $M$ is the mass of the Earth (or other large body), and $r$ is the distance between their centers.

Review Questions

• What variables do you need to know to calculate gravitational potential energy?
• Write down and explain the formula for gravitational potential energy near Earth's surface.
• How does gravitational potential energy change as an object moves higher in a gravitational field?

Related terms

Kinetic Energy:

The energy an object possesses due to its motion, calculated using the formula $KE = \frac{1}{2}mv^2$.

Mechanical Energy:

The sum of kinetic and potential energies in a system. In a closed system with no non-conservative forces acting, it remains constant.

Conservation of Energy:

A principle stating that the total mechanical energy in a closed system remains constant if only conservative forces act on it.