Which one of the following is not the unit of energy?

What is the work done by a coolie walking on a horizontal platform with a load on his head?

$A$ girl of mass $35 \, kg$ sits on a trolley of mass $5 \, kg$. The trolley is given an initial velocity of $4 \, m \, s^{-1}$ by applying a force. The trolley comes to rest after covering a distance of $16 \, m$. $(a)$ What is the work done on the trolley? $(b)$ What is the work done by the girl?

Four persons jointly lift a $250 \,kg$ box to a height of $1 \,m$ and hold it.
$(a)$ Calculate the work done by the persons in lifting the box.
$(b)$ How much work do they do just holding it?
$(c)$ Why do they get tired while holding it? $(g = 10 \,m/s^2)$

The velocity of a body moving in a straight line is increased by applying a constant force $F$ for some distance in the direction of the motion. Prove that the increase in the kinetic energy of the body is equal to the work done by the force on the body.

How is the power related to the speed at which a body can be lifted? How many kilograms will a man working at the power of $100\, W$ be able to lift at a constant speed of $1\, m\, s^{-1}$ vertically (in $, kg$)? $(g = 10\, m\, s^{-2})$