Question

Ramu moves along the periphery of a square field of side $10\text{m}$. He completes travelling one side in $40\text{s}$. What will be the magnitude of distance and displacement at the end of $\text{2 minutes}$ and $\text{20 seconds}$ ?

• A. $35\text{m}$, $35\text{m}$
• B. $35\text{m}$, $5\text{m}$
• C. $25\text{m}$, $10\text{m}$
• D. $35\text{m}$, $10\text{m}$

Answer 1

The correct option is B $35\text{m}$, $5\text{m}$

Distance covered = Length of one side of square field = $10\text{m}$.
Time taken to cover one side of the field, $t$ = $40\text{s}$.
We know, speed = $\frac{\text{distance}}{\text{time}}$.

$\Rightarrow$speed, $s$ = $\frac{10}{40}$ = $0.25{\text{m s}}^{-1}$.

Now, we have to find the magnitude of distance and displacement at the end of $\text{2 minutes}$ and $\text{20 seconds}$.

Here time taken,
$\Rightarrow t$ = $[2\times 60]+20$ =$140\text{s}.$

$\therefore$ Distance covered$=speed\times time$
$\Rightarrow 0.25\times 140$ = $35\text{m}$.

In travelling $35\text{m}$ around a square of perimeter $40\text{m}$, Ramu is $5\text{m}$ off from his initial position.
Therefore, Ramu's displacement is $5\text{m}$.