A truck travelling due to north at `20m s^(-1)` turns west and travels at the same speed. Find the change in its velocity.

Options

A. `40ms^(-1)N-W`
B. `20sqrt(2) ms^(-1) N-W`
C. `40 ms ^(-1)S-W`
D. `20sqrt(2) ms^(-1) S-W`

Answer

D

Explanation

(d ) From the figure
Velocity of truk in north direction `v_(1)=20hatj`
Velocity ot truk in ewst dircation
`v_(2)=-20hatiimpliesDeltav=v_(2)-v_(1)=-20(hati+hatj)`

Change in velocity
`|Deltav|=20sqrt(2)` and direction will be given by
`theta=tan^(-1)(1)=45,i.e.,S-W`