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.

Explanation

We know that the slope of `x to t` graph gives value of average velocity. Here, three graphs of same time intervals are shown.
Velocity in third interval is maximum because its slope is greater.
Velocity in second interval is minimum because its slope is smaller.
Velocities in `1^(st) and 2^(nd)` intervals are positive and in `3^(rd)` interval is negative. Because in `1^(st) and 2 ^(nd)` interval the slope is positive and in `3^(rd)` interval the slope is negative.