Question

Ramu moves along the periphery of a square field of side 10 m. He completes travelling one side in 40 s.then the displacement at the end of 2 minutes and 20 seconds is

• A. 0 m
• B. 5 m
• C. 10 m
• D. 15 m

Answer 1

The correct option is B 5 m

Distance covered=Length of one side of square field = 10 m.
Time taken to cover one side of the field, t = 40 s.
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 = 140 s.
$\therefore$Distance covered = $speed\times time$ = $0.25\times 140$ = 35 m.
In travelling 35 m around a square of perimeter 40 m, Ramu is 5 m off from his initial position.
Therefore Ramu's displacement is 5 m.