Why do you fall in the forward direction when a moving bus brakes to a stop and fall backwards when it accelerates from rest?

What is the momentum of an object of mass $m$, moving with a velocity $v$?

$A$ hockey ball of mass $200 \,g$ travelling at $10 \,m \,s^{-1}$ is struck by a hockey stick so as to return it along its original path with a velocity of $5 \,m \,s^{-1}$. Calculate the magnitude of the change in momentum of the hockey ball due to the force applied by the hockey stick.

Two objects,each of mass $1.5\, kg$,are moving in the same straight line but in opposite directions. The velocity of each object is $2.5\, m/s$ before the collision during which they stick together. What will be the velocity (in $m/s$) of the combined object after collision?

An object of mass $100 \,kg$ is accelerated uniformly from a velocity of $5 \,m \,s^{-1}$ to $8 \,m \,s^{-1}$ in $6 \,s$. Calculate the initial and final momentum of the object. Also, find the magnitude of the force exerted on the object.

$A$ batsman hits a cricket ball which then rolls on a level ground. After covering a short distance,the ball comes to rest. The ball slows to a stop because