What is meant by free fall ? Two bodies, one of mass $1\,g$ and other of mass $1\, kg$ are dropped from the same height in vacuum. Compare the two time intervals in which the two bodies will hit the ground.

A truck is moving on a straight road with uniform acceleration. The following table gives the speed of the truck at various instants of time.

Draw the speed-time graph by choosing a convenient scale. Determine from it

$(i)$ the acceleration of truck

$(ii)$ the distance travelled by the truck in $50$ seconds.

Define 'average speed'. An object moves with a uniform speed of $10\, m s ^{-1}$ for $5 s$ and then with a uniform speed of $5\, m s ^{-1}$ for $10\, s$. Find its average speed.

Answer the following questions

$(i)$ State the type of motion shown by a freely falling stone.

$(ii)$ When a stone is thrown vertically upwards its velocity is continuously decreased. Why ?

$(iii)$ Give an example of a motion in which average velocity is zero, but the average speed is not zero.

The distance$-$time graph of a body is parallel to time axis. The body is