$A$ pair of bullocks exerts a force of $140 \, N$ on a plough. The field being ploughed is $15 \, m$ long. How much work is done in ploughing the length of the field (in $, J$)?

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? $(g = 10 \,m/s^2)$

What is the work done by the force of gravity on a satellite moving around the Earth? Justify your answer.

$A$ person is climbing a palm tree:
$(i)$ What is the work done against the force of gravity?
$(ii)$ What is the work done by the force applied by the person if the person climbs $10 \, m$ and the mass of the person is $45 \, kg$?

What is the work done by the tension in the string of a simple pendulum?

The $CGS$ unit of work is: