Which would require a greater force $-$ accelerating a $2 \ kg$ mass at $5 \ m s^{-2}$ or a $5 \ kg$ mass at $3 \ m s^{-2}$?

When a net force acts on an object,the object will be accelerated in the direction of the force with an acceleration proportional to:

When a missile is fired from a tank,it gets a momentum of $2000 \ kg \ m \ s^{-1}$. If the velocity of the missile is $50 \ m \ s^{-1}$,what will be its mass (in $kg$)?

$A$ 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.

$A$ player catching a moving ball moves his hand backwards. Why?

$A$ $8000 \,kg$ 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.