Question

The speed of a car as a function of time is shown in figure (3-E1). Find the distance travelled by the car in 8 seconds and its acceleration.

Figure

Answer 1

Slope of the v–t graph gives the acceleration.
Slope = $\tan \left(\theta \right)=\frac{20}{8}=2.5\mathrm{m}/{\mathrm{s}}^2$

Area in the v–t graph gives the distance travelled.
Distance travelled = Area of ∆OAB
= $\frac{1}{2}\times 20\times 8=80\mathrm{m}$