A car moving on a straight road due north with a uniform speed of `50 km h^(-1)` when it returns left through `90^(@)`. If the speed remains unchanged after turning process is

Options

A. Zero
B. `50sqrt(2) km h^(-1) S-W direction`
C. `50sqrt(2) km h^(-1) N-W direction`
D. ` 50 km h^(-1) due west`

Answer

B

Explanation

`vec(v)_(i)= 50 hat(j)implies vec(v)_(f)= 50 hat(i)`
`Delta vec(v)_(f)-vec(v)_(i)= -50hat(i)-50hat(j)`
`|Deltavec(v)|= 50sqrt(2) km//h, S-W`