A particle is moving in a circle of radius `r` with speed `v` as shown in the figure. The magnitude of change in velocity in moving from `P` to `Q` is

Options

A. `2v cos 40^(@)`
B. `2 v sin 20^(@)`
C. `2 v cos 20^(@)`
D. none of these

Answer

B

Explanation

velocity at `p=vhatj`
velocity at Q=-v sin `40^(@) hati+v cos 40^(@) hatj`
magnitude of change in velocity `=2 v sin 20^(@)`