For the motion on a straight line path with constant acceleration the ratio of the maqnitude of the displacement to the distance covered is

A truck running at $90\, km h ^{-1}$ is brought to rest over a distance of $25\, m$. Calculate the retardation and time for which brakes are applied.

Account for the following

$(a)$ Name the quantity which is measured by the area occupied below the velocity$-$time graph.

$(b)$ An object is moving in a certain direction with acceleration in the perpendicular directions.

$(c)$ Under what condition is the magnitude of average velocity of an object equal to its average speed ?

$(d)$ An example of uniformly accelerated motion.

$(e)$ A body is moving along a circular path of radius

$(r)$. What will be the distance and displacement of the body when it completes half revolution ?

Distinguish between terms distance and displacement.

The distance$-$time graph of two trains are given below. The trains start simultaneously in the same direction.

$(i)$ How much ahead of $A$ is $B$ when the motion starts ?

$(ii)$ What is the speed of $B$ ?

$(iii)$ When and where $A$ will catch $B$ ?

$(iv)$ What is the difference between the speeds of $A$ and $B$ ?

$(v)$ Is the speed of either trains uniform or non uniform ? Justify your answer.

Explain the following type of motion with one example of each

$(i)$ Acceleration is positive

$(ii)$ Acceleration is negative

$(iii)$ Acceleration is zero.