Question

A glass wind screen whose inclination with the vertical can be changed is mounted on a car. The moves horizontally with a speed of `2m//s`. At what angle `alpha` with the vertical should the wind screen placed so that the rain drops falling vertically downwards with velcoity `6m//s` strike the wind screen perpendicularly?

Answer 1

Correct Answer - `tan^(-1)(3)`
`(V_(C))/(V_(R)) = tan (90-alpha)`
`(2)/(6) = cot alpha`
`tan alpha = 3`