Question

The diagram shows the displacement-time graph for a particle moving in a straight line. The average velocity for the interval $t=0s$ to $t=5s$ is (Displacement is in $m$ and time is in $s$)

• A. $0m{s}^{-1}$
• B. $6m{s}^{-1}$
• C. $-1m{s}^{-1}$
• D. $-2m{s}^{-1}$

Answer 1

The correct option is D $-2m{s}^{-1}$

From the graph it can be seen that the velocity increases from $t=0$ to $t=2s$ and decreases from $t=2s$ to $t=5s$.

The displacement can be found from graph.

$\therefore$ Average velocity$=\frac{Totaldisplacement}{Totaltime}=\frac{20+(-20)+(-10)}{5}$ $=-2m{s}^{-1}$