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

$A$ certain force acting on a $20 \, kg$ mass changes its velocity from $5 \, m \, s^{-1}$ to $2 \, m \, s^{-1}$. Calculate the work done by the force. (in $J$)

$A$ ball is dropped from a height of $10 \, m$. If the energy of the ball reduces by $40 \%$ after striking the ground,how much high can the ball bounce back (in $, m$)? $(g = 10 \, m s^{-2})$

$(a)$ What is meant by potential energy? Is potential energy a vector or scalar quantity?
$(b)$ Give one example of a body having potential energy.

$(a)$ Can a body have energy without having momentum? Explain.
$(b)$ Can a body have momentum without having energy? Explain.

Identify the kind of energy possessed by a running athlete.