Question

A man moves around the boundary of a square plot of side 20 m in 40 s. What is the (a) distance covered
(b) displacement at the end of 2 min and 40 s.?

Answer 1

Answer:

Given side of square =10m, thus perimeter P=40m

Time taken to cover the boundary of 40 m =40 s

Thus in 1 second, the farmer covers a distance of 1 m

Now distance covered by the farmer in 2 min 20 seconds = 1×140=140m

Now the total number of rotation the farmer makes to cover a distance of 140 meters =

perimeter

totaldistance

=3.5

At this point, the farmer is at a point say B from the origin O

Thus the displacement s=

10

2

+10

2

from Pythagoras theorem.

s=10

2

=14.14m