Question

The efficiency to machine is 75% , if this machine raises a load of 150kg , through a vertical height of 20m,calculate the workdone by the labourer using the machine (g=10m/s square) ?

Answer 1

weight = force = m g = 150 * 10
work = force * distance = 150 * 10 * 20 = 30,000 Joules work out
= .75 work in
so
work in = 30,000/.75 Joules

Answer 2

(150 * 20 * g) / .75 ... Joules