Figure. gives a speed-time graph of a particle in motion along a constant direction. Three equal intervals of time are shown. In which interval is the average acceleration greatest in magnitude ? In which interval is the average speed greatest ? Choosing the positive direction as the constant direction of motion, give the signs of v and a in the three intervals. What are the accelerations at the points A, B, C and D ?

Explanation

Acceleration magnitude greatest in 2, speed greatest in 3, `upsilon gt 0` in 1, 2 and 3, `a gt 0` in 1 and 3, `a lt 0` in 2, a = 0 at A, B, C, D.