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

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

Define work. Write an expression for work in terms of force and displacement. State the $SI$ unit of work done.

$A$ box of mass $10 \, kg$ is placed at point $A$ on a horizontal surface. It is moved to point $B$,which is at a distance of $2 \, m$ from $A$. If the line joining $A$ and $B$ is horizontal,find the work done by the gravitational force on the box. Justify your answer. $(g = 10 \, m s^{-2})$ (in $, J$)

$A$ person continues to push a heavy mass for some time but fails to move it. What is the work done by him?

The work done by a force on a body will be positive if the: