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. `40 m//s NW`
B. `40 m//s SW`
C. `20sqrt(2) m//s NW`
D. `20 sqrt(2) m//s SW`

Answer

D

Explanation

`Delta vec(v) = vec(v_(2)) - vec(v_(1)) = vec(v_(2)) + (-vec(v_(1)))`
`|Delta vec (v)| = Delta v = 20 sqrt(2) m//s , theta = 45^(@)`
Change in the velocity : `20 sqrt(2) m//s , SW`