Identify the energy possessed by a rolling stone.

$A$ light body and a heavy body have the same kinetic energy. Which one will have the greater momentum?

$A$ man rowing a boat upstream is at rest with respect to the shore. Is he doing work?

State whether the following statement is true or false:
In order to get minimum work,the angle between force and displacement should be $90^{\circ}$.

$A$ man weighing $50 \, kg$ lifts a weight of $30 \, kg$ to the top of a building $10 \, m$ high. Find the work done by him. (Take $g = 9.8 \, m s^{-2}$) (in $, J$)

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.