Question

The diagram shows the displacement-time graph for a particle moving in a straight line. The average velocity for the interval $t=2s$ to $t=5s$ is (Displacement is in $m$ and time is in $s$)

• A. $0m{s}^{-1}$
• B. $-5m{s}^{-1}$
• C. $-10m{s}^{-1}$
• D. $10m{s}^{-1}$

Answer 1

The correct option is C $-10m{s}^{-1}$

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

The displacement can be found from graph.

$\therefore$ Average velocity$=\frac{\text{Total displacement}}{\text{Total time}}=\frac{-10-20}{3}$ $=-10m{s}^{-1}$