Arun
Last Activity: 6 Years ago
Dear Aabha
The resultant velocity of rain drops will be the vector sum of the rain drop speed (vertical) and the horizontal wind speed.
the magnitude of the result velocity of the rain drops =
√(625*3+625) = 50 m / sec
the direction of the resultant velocity vector with the vertical
= tan ⁻¹ (25/25* root(3)) = 30 deg.
The umbrella should be pointed in the direction opposite to the resultant velocity of the rain drops. So it should be in the direction 30 deg. inclination to the vertical opposite to the direction of wind., towards West.
or, 60 deg. with the horizontal (West) towards the vertical.
Hope it helps
Regards
Arun (askIITians forum expert)