Question

A position $\left(X\right)$ of a particle moving along $x-$ axis varies with time $\left(t\right)$ as shown in figure. The average acceleration of particle in time interval $t=0$ to $t=8s$ is

Answer 1

Average acceleration, $a=\frac{v_2-v_1}{t}$. . . . . . .(1)

From the graph, the initial velocity is the slope of the graph in between the 0sec to 2sec

$v_1=\frac{40}{2}=20m/s$

Final velocity is the slope of the graph in between 6sec to 8sec

$v_2=\frac{-40}{2}=-20m/s$

Put the value of $v_1,v_2$ in equation (1), we get

$a=\frac{-20-20}{8}=\frac{-40}{8}=-5m/s^2$