Question 906924
When the wind strikes a surface at right angle, the total force it exerts against the surface approximately varies jointly as the area of the surface and the square of the velocity of the wind. 
Compare the force exerted by the wind whose velocity is 15 kilometers per hour on a surface 15 square meters in area 
Force = 15*15^2 = 15^3 = 3375
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with that exerted by the wind whose velocity is 40 kilometers per hour on a surface 25 square meters in area.
Force = 25*40^2 = 40,000
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Cheers,
Stan H.