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 $1.7 \, m \, s^{-2}$?

$A$ $8000 \,kg$ engine pulls a train of $5$ wagons,each of $2000 \,kg$,along a horizontal track. If the engine exerts a force of $40000 \,N$ and the track offers a friction force of $5000 \,N$,then calculate the acceleration (in $m/s^2$) of the train.

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.

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.

$A$ bullet of mass $10\, g$ travelling horizontally with a velocity of $150\, m/s$ strikes a stationary wooden block and comes to rest in $0.03\, s$. Calculate the distance of penetration of the bullet into the block. Also,calculate the magnitude of the force exerted by the wooden block on the bullet.