A glass wind screen whose inclination with the vertical can be changed is mounted on a car. The car moves horizontally with a speed of 2m/s. At what angle α with the vertical should the wind screen be placed so that rain drops falling vertically downwards with velocity 6 m/s strike the wind screen perpendicularly?
(a) tan-1(1/3)
(b) tan-13
(c) cos-13
(d) sin-1(1/3)
