A bird is flying towards north with a velocity `40 km h^-1` and a train is moving with velocity `40 km h^-1` towards east. What is the velocity of the bird boted by a man in the train ?

Options

A. `40 sqrt(2) km h^-1 N - E`
B. `40 sqrt(2) km h^-1 S - E`
C. `40 sqrt(2) km h^-1 N - W`
D. `40 sqrt(2) km h^-1 S - W`

Answer

C

Explanation

(c ) To find the relative velocity of bird w.r.t. train, superimpose velocity `-vec V_T` on both the objects. Now as a result of it, the train is at rest, while the bird possesses two velocities, `vec V_B` towards north and `-vec V_T` along west.
`|vec V_(B T)| = sqrt(|vec V_B|^2 + |- vec V_T|^2))` [By formula, `theta = 90^@`]
=`sqrt(40^2 + 40^2) = 40 sqrt(2) km h^-1` north - west.
(a) ,