Question

A woman starts from her home at 9.00 am, walks with a speed of 5 km $\text{h}^{-1}$on a straight road up to her office 2.5 km away, stays at the office up to 5.00 pm, and returns home by an auto with a speed of 25 $\text {km}$ $\text{h}^{-1}$. Choose suitable scales and plot the x-t graph of her motion.

Answer 1

Speed of the woman = 5 $\text{km}/\text h$
Distance between her office and home = 2.5 $\text{km}$
Time taken = $\frac{\text{Distance}}{\text{Speed}}$
= $\frac{25.5}{5}$ = 0.5$\text h$ = 30 $\text {min}$
It is given that she covers the same distance in the evening by an auto.
Now, speed of the auto = 25 $\text{km}/\text h$
Time taken = $\frac{\text{Distance}}{\text{Speed}}$
= $\frac{2.5}{25}$ = $\frac{1}{10}$ = 0.1 $\text h$ = 6 $\text {min}$
The suitable x-t graph of the motion of the woman is shown in the given figure.