Question

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

• A. $35m$, $35m$
• B. $35m$, $5m$
• C. $25m$, $10m$
• D. $35m$, $10m$

Answer 1

The correct option is B

$35m$, $5m$

Distance covered = Length of one side of square field = $10m$.
Time taken to cover one side of the field, $t$ = $40s$.
We know, speed = $\frac{distance}{time}$.
$\Rightarrow$speed, s = $\frac{10}{40}$ = $0.25m{s}^{-1}$.
Now we have to find the magnitude of distance and displacement at the end of 2 minutes and 20 seconds.
Here time taken, $t$ = $[2\times 60]+20$=$140s.$
$\therefore$Distance covered = $speed\times time$ = $0.25\times 140$ = $35m$.
In travelling $35m$ around a square of perimeter $40m$, Ramu is $5m$ off from his initial position.
Therefore, Ramu's displacement is $5m$.