A particle is moving with a uniform velocity. What is its acceleration? 

The driver of a car travelling at $72 {\mathrm{kmh}}^{-1}$ applies the brakes and accelerates uniformly in the opposite direction at the rate of $5 {\mathrm{ms}}^{-2}$. How long the car will take to come to rest? How far will the car cover before coming to rest.

The figure below shows the distance-time graph of three motorcyclists $A,B$ and $C$. On the basis of this graph answer the following questions:

Which of them is travelling fastest?

The figure below shows the distance-time graph of three motorcyclists $A,B$ and $C$. On the basis of this graph answer the following questions:

Are all the three ever at the same point on the road?