With a horizontal vector v of which 10 m / s, raindrops fall at an angle of 30 degrees to the vertical.

With a horizontal vector v of which 10 m / s, raindrops fall at an angle of 30 degrees to the vertical. At what horizon v of the wind will the drops fall at an angle of 60 degrees to the vertical.

Given:

v1 = 10 m / s – horizontal wind speed.

a1 = 30 degrees – the angle at which the raindrops fall.

a2 = 60 degrees.

It is required to determine the wind speed v2 at which the angle of incidence of the raindrops is a2.

Let the raindrops fall at a certain speed w. Then, from the condition of the problem:

w = v1 * ctg (a1) = 10 * 1.7 = 17 m / s.

In order for the angle of inclination of the raindrops to be 60 degrees, the equality must be fulfilled:

v2 * sin (a2) = w * cos (a2), hence:

v2 = w * tg (a2) = 17 * 1.7 = 28.9 m / s.

Answer: the wind speed should be 28.9 m / s.