In the wheel and axel system below 12 lbs. Of effort is used to turn the axel, which provided 70 lbs. Of resistance. If the diameter of the wheel is 15 in., what is the maximum diameter of the axel?

2.57in

Explanation:

Let's assume the efficiency of the wheel and axle system is 100%

Efficiency = MA/VR ×100

100 = MA/VR × 100

MA/VR = 1

mechanical Advantage MA = Load/effort

MA = 70/12

MA = 5.83

Velocity ratio VR = Diameter of wheel/diameter of axle

VR = 15/d

Substitute into the formula the given data and get d

1 = (70/12)÷(15/d)

1 = 70/12×d/15

1 = 70d/180

Cross multiply

180 = 70d

d = 180/70

d = 18/7

d = 2.57in

Hence the maximum diameter of the axle is 2.57in

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