The “eggbeater” wind turbine is stopped by using spoilers which consist of 20-lb blocks that slide out along the blades when the blades are turning. As the spoilers travel along the blade, they create a drag on the blade that slows and eventually stops the blade. If it is observed that the spoilers reach point A on the blade, determine the required minimum speed of the spoilers needed to maintain this position, and also the normal force they exert on the blade when in this position. The blade has the shape of a parabola, as shown in the figure. The coefficient of static friction between the spoilers and the blades is μ_s = 0.3.

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20 ft 20 ft-10 ft- -y² = 400 - 20x A -20 ft- ·X