Solve the following :
Question:

From the velocity-time plot shown in the given figure, find the distance travelled by th the first 40 seconds. Also find the average velocity during the period.

Solution:

Distance $=$ Area of v-t graph

$=\left(\frac{1}{2} \times 20 \times 5\right)+\left(\frac{1}{2} \times 20 \times 5\right)$

$=100 m$

Displacement $=\left(\frac{1}{2} \times 20 \times 5\right)+\left(-\frac{1}{2} \times 20 \times 5\right)$

Displacement $=0$

$\overrightarrow{V_{\text {avg }}}=\frac{\text { displacement }}{\text { time }}$

$\vec{V}_{\text {avg }}=0$