$A$ stone of $1\, kg$ is thrown with a velocity of $20\, m\ s^{-1}$ across the frozen surface of a lake and comes to rest after travelling a distance of $50\, m$. What is the force of friction (in $N$) between the stone and the ice?

Explain,why is it difficult for a fireman to hold a hose,which ejects large amounts of water at a high velocity.

An automobile vehicle has a mass of $1500 \, kg$. What must be the force (in $N$) between the vehicle and road if the vehicle is to be stopped with a negative acceleration of $1.7 \, m \, s^{-2}$?

Using a horizontal force of $200\, N$,we intend to move a wooden cabinet across a floor at a constant velocity. What is the friction force (in $N$) that will be exerted on the cabinet?

In the following example, try to identify the number of times the velocity of the ball changes:
"$A$ football player kicks a football to another player of his team who kicks the football towards the goal. The goalkeeper of the opposite team collects the football and kicks it towards a player of his own team".
Also identify the agent supplying the force in each case.

$A$ 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.