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 $5 \ m s^{-1}$?

$A$ steam engine of mass $3 \times 10^{4} \text{ kg}$ pulls two wagons,each of mass $2 \times 10^{4} \text{ kg}$,with an acceleration of $0.2 \text{ m s}^{-2}$. Neglecting frictional forces,calculate the:
$(i)$ force exerted by the engine.
$(ii)$ force experienced by each wagon.

Write the relation for the collision of two balls $A$ and $B$ and state the related law.

Give an example to show that friction is an important factor in satisfying Newton's third law of motion.

$(i)$ Name the property of bodies to resist a change in their velocity.
$(ii)$ What is the relationship between force and acceleration?
$(iii)$ What name is given to the product of mass and velocity of a body?
$(iv)$ Which physical quantity corresponds to the rate of change of momentum?
$(v)$ Name the principle on which a rocket works.

Name the physical quantity whose $SI$ unit is "newton".