# Uniform acceleration (velocity-time graphs)

**Classical Mechanics**Level pending

A train accelerates uniformly from rest to a speed v m/s. It continues at this speed for a period of time and then decelerates uniformly to rest. In travelling a total distance d metres the train accelerates through a distance pd metres and decelerates through a distance qd metres, where p < 1 and q < 1. (i) Draw a speed-time graph for the motion of the train. If the average speed of the train for the whole journey is \(\frac{v}{p+q+d}\), find the value of b.