Question

Question 14
A girl walks along a straight path to drop a letter in the letterbox and comes back to her initial Position. Her displacement–time graph is shown in the figure given below. Plot a velocity–time graph for the same.

Answer 1

Initially, at time $t=0$, the displacement $=0$ and at time $t=50s$, displacement $=100m$
We know, $velocity=\frac{displacement}{time}=\frac{100-0}{50-1}=2m{s}^{-1}$
and after time $t=50s$, the velocity is decreasing at a uniform rate.
At $t=100s$, displacement $=0$
Therefore in this case, $velocity=\frac{0-100}{100-50}=-2m{s}^{-1}$
Therefore the velocity-time graph for the above-mentioned displacement-time graph will look like