AIPMT> Rain is falling at the speed of 25sqrt(3)...

Rain is falling at the speed of 25sqrt(3) m/s vertically The wind blows west to east at a speed of 25 m/s. Find the velocity of rain as experienced by a person standing on the ground. I am gettong the value of angle = 30 degrees but it is given 60 degrees in solution.

Aabha Misra , 6 Years ago

Grade 12th pass

1 Answers

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)