Define potential energy. Write an expression for potential energy. Write the $SI$ unit of potential energy.

(N/A) Potential energy is the energy possessed by an object by virtue of its position or configuration.
The expression for gravitational potential energy is $PE = mgh$,where $m$ is the mass of the object,$g$ is the acceleration due to gravity,and $h$ is the height above the reference level.
The $SI$ unit of potential energy is the joule $(J)$.