$(i)$ Define the term potential energy. Write the $SI$ unit of potential energy.
$(ii)$ $A$ body of mass $50 \, kg$ is situated at a height of $10 \, m$. What is its potential energy? (Given $g = 10 \, m s^{-2}$)

(D) $(i)$ The energy possessed by an object due to its position or configuration is called potential energy. The $SI$ unit of potential energy is joule $(J)$.
$(ii)$ Given: mass of the body $(m) = 50 \, kg$,height $(h) = 10 \, m$,and acceleration due to gravity $(g) = 10 \, m s^{-2}$.
The formula for potential energy $(PE)$ is $PE = m \times g \times h$.
Substituting the values: $PE = 50 \, kg \times 10 \, m s^{-2} \times 10 \, m = 5000 \, J$.
Therefore,the potential energy of the body is $5000 \, J$.