Question

Time-velocity graph of a particle is shown in fig. Find its instantaneous acceleration at following intervals :
(i) at t = 3s
(ii) at t = 6s
(iii) at t = 9s

Answer 1

As we know that in the velocity-time graph the slope of the graph gives the acceleration of the body

(i) Instantaneous acceleration at t = 3 s, is given as

a = slope of line AB

Since AB is a straight line so its slope is Zero so the acceleration is also zero.

(ii) Instantaneous acceleration at t = 6 s, is given as

a = slope of line BC

$\frac{CM}{BM}$ = $\frac{40}{4}$ = 10 m/$s^2$

(iii) Instantaneous acceleration at t = 9 s, is given as

a = slope of line CD

$\frac{CG}{GD}$ = $\frac{100}{2}$ = –50 m/$s^2$