Question

Write down the relation between the load and the effort of the pulley system.

Answer 1

For the block-and-tackle system with two pulleys in each block:

L = 4E

where L is the load and E is the effort.

There are four string segments supporting the movable block, so:

L = 4T

E = T

∴ L = 4E

This relation is valid for an ideal pulley system, with negligible friction and pulley weight.