Question

The velocity-time graph of a particle in straight-line motion is shown in the figure. The particle starts its motion from the origin.
Find the average acceleration from $2\text{s}$ to $6\text{s}$.

• A. $-1{\text{m/s}}^2$
• B. $-1.5{\text{m/s}}^2$
• C. $1.5{\text{m/s}}^2$
• D. $-1{\text{m/s}}^2$

Answer 1

The correct option is B $-1.5{\text{m/s}}^2$

Average acceleration in a particular interval is given,
$a_{avg}=\frac{\text{change in velocity}}{\text{time interval}}$
From the graph, we can say that at $t=2s,v=4\text{m/s}\text{and at}t=6\text{s},v=-2\text{m/s}$
$\therefore a_{avg}=\frac{-2-4}{4}=\frac{-6}{4}=\frac{-3}{2}=-1.5{\text{m/s}}^2$