The diagram shown represents a block-and-tackle pulley system on which an effort of W Newtons supports a load of 120.0N. If the efficiency of the machine is 40, then the value of W is?
Given Data:
Efficiency = 40% Load = 120N, V.R = 6 (Number of Pulleys)
Efficiency = M.AV.R×100\frac{\text{M.A}}{\text{V.R}} \times 100V.RM.A×100
40 = M.A6×100\frac{\text{M.A}}{6} \times 1006M.A×100
6 * 40 = 100 M.A
M.A = 240100\frac{240}{100}100240 → 2.4
Where M.A = LoadEffort\frac{\text{Load}}{\text{Effort}}EffortLoad
2.4 = 120Effort\frac{120}{\text{Effort}}Effort120
: Effort = 1202.4\frac{120}{2.4}2.4120 → 50N
