A block and tackle have 4 pulleys which is used to raise a load of 450N through a height of 12m. If the workdone against friction is 1000J, calculate the workdone by the effort, the efficiency of the system and the effort applied.

work on load = 450 N * 12 m = 5.4kJ

effort distance = 4 * 12 m = 48 m

effort work = 1000 J + 5.4 kJ = 6.4 kJ

efficiency = (work on load) / effort work

effort applied = (effort work) / (effort distance)