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Mechanics

A car is moving on a horizontal road with a speed of 20 m/s. Rain is falling vertically downwards with a speed of 10m/s. If the raindrops strike the windscreen of the car normally, then the angle made by the windscreen with the vertical?

Ans tan-1(.5)

Profile image of Nehal Wani
16 Years agoGrade
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1 Answer

Profile image of Vanya Saxena
16 Years ago

Let the velocity of the car be Vc and that of the rain be Vr Now on plotting the figure we get a right angled triangle with its perpendicular as Vr=10m/s and the horizontal component i.e. the base as Vc=20 m/s Now since the angle required is the vertical angle off the triangle

therefore

                                tanΦ=Vc/Vr

                                tan Φ=1/2

                                   Φ=tan-1(.5)