Question

when a man is standing , rain drops appear to him falling at 60° from the horizontal from his front side .when he is travelling at 5 kmph on a horizontal road they appear to him falling at 30° from the horizontal from his front side.the actual speed of the rain is (in kmph)

Answer 1

Answer:

Let speed of the rain be v km/h.

At rest rain makes angle 60 degree with horizontal.

When the man is moving at u=5km/h, rain appears to fall at 30 degree with horizontal.

So angle between velocity of rain and man is 60 degree while the resultant makes angle 30 degree with the velocity of man.

∴tan30=

u+vcos60/vsin60

Solving actual speed of rain, v=5km/h