Give examples demonstrating inertia of direction.

What do you mean by an impulse of force? Give an example.

Why it is not possible for a man to walk in space?

Explain linear momentum with a suitable example.

If action and reaction act on a body, how is the motion of the body possible?

What is the momentum of a boy of mass $40 \mathrm{kg}$ when he walks with a uniform velocity of $2 \raisebox{1ex}{$\mathrm{m}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{s}$}\right.$.

A force of $20 \mathrm{N}$ towards east is balanced by an unknown force $f$. What will be the magnitude and direction of unknown force?

The velocity-time graph of a body moving on a horizontal surface is shown in the adjoining figure. The mass of the body is $20 \mathrm{g}$. How much force does the surface exert on the body to bring it to rest?

Calculate the change in momentum of a car of mass $1500 \mathrm{kg}$ when its speed increases from $18 \mathrm{km}/\mathrm{h} \mathrm{to} 90 \mathrm{km}/\mathrm{h}$ uniformly.