From the displacement-time graph of a cyclist, given in figure, find (i) The average velocity in the first 4 s, (ii) The displacement from the initial position at the end of 10 s (iii) The time after which he reaches the starting point.

(i) Average velocity = 10 \over 4

= 2.5 ms^-1.

Hence, average velocity of the car is 2.5 ms^-1.

(ii) From the graph, we get,

Displacement = final position – initial position

Substituting the values from the graph, for the first 10 s, we get,

Displacement = -10 – 0 = -10 m

Hence, displacement from the initial position at the end of 10 s = – 10 m

(iii) The cyclist would reach the start point two times, one at the 7 s and the other at 13 s.