Q.

A person moves 30 m north, then 30 m east, then 302 m south-west. His displacement from the original position is

1 zero  
2 28 m towards south  
3 10 m towards west  
4 15 m towards east  

Ans.

(1)

Resolving displacement 302 m south-west into two rectangular components, we get

Displacement in south =302cos45°=302×(12)=30 m

Displacement in west =302sin45°=302×(12)=30 m

∴   Effective displacement 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.