When the man is at rest with respect to the ground, the rain comes to him at an angle 30∘ with the vertical. This is the direction of the velocity of raindrops with respect to the ground. Here,
→
v
r,g= velocity of the rain with respect to the ground
→
V
m,g= velocity of the man with respect to the ground
and
→
v
r,m= velocity of the rain with respect to the man. We have,