Question

A farmer moves along the boundary of a square field of side 10m in 40s . What will be the magnitude of displacement of the farmer at end of 2 minutes 20 seconds from his initial position?????please give the answer fast

Answer 1

$10 \sqrt{2}$

Answer 2

As he covers 10m in 10s so he covers 60m in 60s.
In 2 minutes he covers 120m which is equal to three rounds of the field.
So in remaining 20s he will cover 20m.

Consider the square field ABCD.

If he has started from point A then in first three rounds the displacement is zero as he comes to initial point back. The next 20m , he will reach diagonally opposite point to A which is C .
So the displacement will be equal to the length of the diagonal, which is,
AC=√(AB^2+BC^2)
=√(100+100)
= 10√2