A particle is observed to move along a straight line with its velocity changing irregularly with time. Answer the following questions based on this motion:
a. (i) Define (a) average acceleration and (b) instantaneous acceleration.
b. (ii) Describe with the help of a velocity–time graph how each of the above accelerations can be obtained graphically.
c. (iii) During a particular interval the velocity of the particle rises uniformly from 5ms−1 to 20ms−1 in 3.0s. Calculate the average acceleration for this interval. Would this numerical value necessarily be equal to the instantaneous acceleration at t=1.5s? Give reason for your answer.