$A$ girl of mass $50 \, kg$ jumps out of a moving boat of mass $300 \, kg$ onto the bank with a horizontal velocity of $3 \, m s^{-1}$. With what velocity will the boat begin to move backwards (in $, m s^{-1}$)?

Using the second law of motion,derive the relation between force and acceleration. $A$ bullet of $10 \, g$ strikes a sandbag at a speed of $10^3 \, m \, s^{-1}$ and gets embedded after traveling $5 \, cm$. Calculate:
$(i)$ The resistive force exerted by the sand on the bullet.
$(ii)$ The time taken by the bullet to come to rest.

$A$ car starts from rest and rolls down a hill with constant acceleration. It travels a distance of $800 \ m$ in $10 \ s$. Find its acceleration. Also,find the force acting on it if its mass is $800 \ kg$.

There are three solids made up of aluminium,steel,and wood,of the same shape and same volume. Which of them would have the highest inertia?

$A$ force can be completely described by

Name the unbalanced force which slows down a moving bicycle when we stop pedalling it.