A block and tackle system consisting of a 5 pulleys is used to raise a load of 400N through a height of 10cm. If the work done against friction is 100J.calculate the work done by the effort, the efficiency of the machine, the effort applied

Answer 1

work output = 400 N * 0.10 m = 40 Joules
work input = 40 + 100 = 140 Joules
eff = 100 * 40/140 = 28.6 % efficient
I do not know your pulley arrangement so can not calculate input effort force