Question

A car with a vertical windshield moves in a rain storm at a speed of 40km/hr. the rain drops fall vertically with a constant speed of 20m/s. the angle at which rain drops strike the windshield is

Answer 1

Let θ be the angle at which raindrop falls at an angle in vertical direction.To the driver who is driving bus, raindrops has both vertical velocity component and horizontal velocity component in a direction opposite to the direction of velocity vector of bus...Therefore, 

The raindrops, appear to move in a direction at an angle θ relative to the vertical and given by
Tanθ=vb/vr
θ=Tan⁻¹ [Vc/vr]
vc=[40x1000/3600]
=11.11

θ=tan⁻¹ [11.11/20]

θ=tan⁻¹ [0.555]

θ=29.1 °

Answer 2

Answer:

tan^-1 5/9

Explanation:

it is very simple.

firstly convert 40 km/hr into m/s

40*5/18 = 100/9

now according to the rule.

angle = tan^ -1 vm/vr

100/9 * 1/20 (reciprocate of 20 is done because we have to divide)

=5/9

hope it's useful