Write true or false for the following statements

A motion is said to be uniform, if a body undergoes equal displacements in equal intervals of time.

Define velocity.

Area under speed$-$time graph is equal to the

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 $+g$.

A body moving with uniform acceleration has velocities $20 \,m s ^{-1}$ and $30\, m s ^{-1}$. when passing two points $A$ and $B$. Then the velocity midway between $A$ and $B$ is