Potential energy

Definition

Potential energy is the stored energy of an object due to its position in a force field, such as gravitational or elastic fields. It is a scalar quantity and can be converted into kinetic energy.

5 Must Know Facts For Your Next Test

1. Gravitational potential energy near Earth's surface is given by $U = mgh$, where $m$ is mass, $g$ is acceleration due to gravity, and $h$ is height above the reference point.
2. Elastic potential energy stored 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 depends only on the initial and final positions, not on the path taken (conservative forces).
4. In a closed system, total mechanical energy (kinetic + potential) remains constant if only conservative forces are involved.
5. Potential energy can be converted into other forms of energy like kinetic or thermal during physical processes.

Review Questions

• How do you calculate gravitational potential energy near Earth's surface?
• What formula represents elastic potential energy in a stretched or compressed spring?
• Why does potential energy depend only on initial and final positions when dealing with 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, depending only on initial and final positions, such as gravity.

Mechanical Energy:

The sum of kinetic and potential energies in a system. In the absence of non-conservative forces, it remains constant.