Question

Figure (3−E6) shows x-t graph of a particle. Find the time t such that the average velocity of the particle during the period 0 to t is zero.

Figure

Answer 1

Consider point B₁ at 12 s.



At t = 0 s, S = 20 m and at t = 12 s, S = 20 m.
For the time interval 0–12, change in the displacement is zero.
$\mathrm{Average}\mathrm{velocity}=\frac{\mathrm{Displacement}}{\mathrm{Time}}=0$
Hence, the time is 12 seconds.