Potential energy

Definition

Potential energy is the stored energy of an object due to its position or state. It can be converted into kinetic energy when the object's position or state changes.

5 Must Know Facts For Your Next Test

1. Gravitational potential energy is given by $U = mgh$, where $m$ is mass, $g$ is gravitational acceleration, and $h$ is height above a reference level.
2. Elastic potential energy in a spring is calculated using $U = \frac{1}{2} k x^2$, where $k$ is the spring constant and $x$ is the displacement from equilibrium.
3. Potential energy is a scalar quantity and has units of joules (J).
4. The work done by conservative forces, like gravity, can be described as the change in potential energy.
5. In a system with only conservative forces, mechanical energy (the sum of kinetic and potential energies) remains constant.

Review Questions

• What formula represents gravitational potential energy?
• How do you calculate the elastic potential energy stored in a compressed or stretched spring?
• Why does mechanical energy remain constant in a system with only conservative forces?

Related terms

Kinetic Energy: The energy an object possesses due to its motion, given by $KE = \frac{1}{2} mv^2$ where $m$ is mass and $v$ is velocity.

Conservative Force: A force that does work independent of the path taken, resulting in no net change in mechanical energy when moving an object around a closed loop.

Mechanical Energy: The sum of kinetic and potential energies in a system.