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Five pulleys are arranged in the second system of pulleys. When not loaded the effort required to raise the movable block is 35N. Further wastage in friction increases the pull at the rate of 3% of the load lifted. What is the effort required to raise a load of 2kN?

Five pulleys are arranged in the second system of pulleys. When not loaded the effort required to raise the movable block is 35N. Further wastage in friction increases the pull at the rate of 3% of the load lifted. What is the effort required to raise a load of 2kN? Correct Answer 495 N

n = no. of pulleys = 5 Frictional effort at zero loading = 35N Frictional effort at 2 kN loading = 35 + 2000 x 3/100 = 95 N When the system is considered frictionless nP = W 5P = 2000 P = 400 N Hence total effort = 400 + 95 = 495 N.

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