Question

A person walking at 4 m/s finds rain drops falling slantwise in to his face with a speed of 4 m/s at an angle of 30° with the vertical. Show that the actual speed of the raindrops is 4 m/s.

Answer 1

Hii dear,

# Given-
Speed of walking man,
vm = 4 m/s
vrm = 4 m/s
θ = 30°

# To prove-
Vr = 4 m/s

# Proof-
Velocity of rain wrt man is calculated by formula,
vrm = √(vr^2 + vc^2 + 2vcvrcosθ)
4 = √(4^2 + vr^2 + 2×4×vr×cos30)
Solving this, we'll get
vr = 4 m/s

Thus proved.

Hope that was useful...