Question

A person moves 30 m north, then 20 m east and finally `30sqrt(2)m` south-west. This displacement from the original position is :
A. Zero
B. `28 m` towards south
C. `10 m` towards west
D. `15 m` towards east

Answer 1

Correct Answer - A
Resolving displcement `30sqrt(2)` south-west into two retangular components, we get
Displacement `= 30sqrt(2)cos 45^(@)= 30 sqrt(2)xx(1/sqrt(2))= 30m`
`:.` Effective displcement due to `30 m` north and `30 m` south is zero.
Also effective displacement due to `30 m` east and `30 m` west is zero.