Q 3.21 Figure gives the x-t plot of a particle in one-dimensional motion. Three different equal intervals of time are shown. In which interval is the average speed greatest, and in which is it the least? Give the sign of average velocity for each interval.
The average speed is greatest in interval 3 and least in interval 2 as the average of the magnitude of the slope is maximum in 3 and minimum in 2.
Average velocity is positive in interval 1 and interval 2 as the slope is positive over these intervals and average velocity is negative in interval 3 as the slope is negative over this interval.