$A$ goalkeeper in a game of football pulls his hands backwards after holding the ball shot at the goal. This enables the goalkeeper to

Newton's second law of motion gives us a measure of

What would be the force required to stop a car of mass $1000 \ kg$ and a loaded truck of mass $10000 \ kg$ in $2 \ s$,if they are moving with the same velocity of $5 \ m s^{-1}$?

$(a)$ Define force and state three possible effects of force on an object.
$(b)$ $A$ motorcycle is moving with a velocity of $90 \, km \, h^{-1}$ and it takes $5 \, s$ to stop after the brakes are applied. Calculate the force exerted by the brakes on the motorcycle if its mass along with the rider is $200 \, kg$.

What is the $SI$ unit of force?

If the time taken to bring a ball to rest from a certain velocity $v$ is reduced to half,what will be the changes in values of
$(a)$ Initial and final momentum.
$(b)$ Change of momentum.
$(c)$ Rate of change of momentum.