Science and Mathematics for Engineering 6th Edition by John Bird

Exercise 6

A load of $30 \mathrm {~kg}$ is lifted by a three-pulley system and the app lied effort is $140 \mathrm {~N}$ . Calculate, taking g to be $9.8 \mathrm {~m} / \mathrm { s } ^ { 2 }$ , (a) the force ratio, (b) the movement ratio, (c) the efficiency of the system.