A trolley, while going down an inclined plane, has an acceleration of $2 \,m \,s^{-2}$. What will be its velocity(in $cm\,s ^{-1}$) $3\, s$ after the start ?

A train is travelling at a speed of $90\, km \,h^{-1}$. Brakes are applied so as to produce a uniform acceleration of $- 0.5\, m s^{-2}$. Find how far(in $m$) the train will go before it is brought to rest.

An athlete completes one round of a circular track of diameter $200\, m$ in $40\, s$. What will be the distance covered and the displacement at the end of $2 \,min$ $20 \,s$ ?

A driver of a car travelling at $52\, km\, h^{-1}$ applies the brakes and accelerates uniformly in the opposite direction. The car stops in $5\, s$. Another driver going at $3 \,km \,h^{-1}$ in another car applies his brakes slowly and stops in $10\, s$. On the same graph paper, plot the speed versus time graphs for the two cars. Which of the two cars travelled farther after the brakes were applied ?

Abdul, while driving to school, computes the average speed for his trip to be $20 \,km\,h^{-1}$. On his return trip along the same route, there is less traffic and the average speed is $40\, km \,h^{-1}$. What is the average speed(in $km\,h ^{-1}$) for Abdul's trip?