a glass wind screen whose inclination with the vertical can be changed is mounted on a car the car - Physics - Motion In A Plane

Question

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 alpha with the vertical should the wind
screen be placed so that the rain drops falling vertically
downwards with velocity 6 m/s strike the wind screen
perpendicularly?

Himanshu · Accepted Answer

Velocity of rain with respect to car should be perpendicular to the screen $r e l a t i v e v e l o c i t y = \vec{v_{r a i n}} - \vec{v_{c a r}}$

$\tan α = \frac{V_{r}}{V_{c}} = \frac{6}{2} = 3 α = \tan^{- 1} 3$