Mention the nature of motion of a body if its displacement$-$time graph is a straight line parallel to time axis.

Mention some uses of velocity$-$time graphs.

A person standing at $A$ goes to $B$ by following any of the paths $1,2$ or $3 .$ Which path we can measure to find the average velocity ?

Two stones are thrown vertically upwards simultaneously with their initial velocities $u _{1}$ and $u _{2}$ respectively. Prove that the heights reached by them would be in the ratio of $u_{1}^{2}: u_{2}^{2}$ (Assume upward acceleration is $-\,g$ and downward acceleration to be $+g$.

Name the force which is responsible for change in position or state of an object.