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A pulley system has an efficiency of 87.5 percent.
How much of the rope must be pulled in if a force of
648 N is needed to lift a 150 kg desk 2.46 m?
(Disregard friction.)

Respuesta :

chriscat345

Answer:

work done on desk = m g h = 105 * 9.81 * 2.46 = 2534 Joules

Explanation:

so work in = 2534 / 0.875 = 2896 Joules

that is your 648 times distance your hand moved holding the rope

2896 = 648 * x

4.47 meters

I think maybe a typo, 648 N is too big, maybe 64.8 ? Any block and tackle system does better than that.