Have you looked at the working crane? The simplest crane like machines were used in ancient Egypt for building pyramids.
Cranes have a heavy wire rope called a cable, that passes through a group of pulleys.
A single pulley can change the direction of force.
Pulleys make it seem easier to move heavy loads.
Let's make a crane!
You need :a long stick, 2 thread rolls, 2 nails, a plastic cup, some string, a papet clip, some tape,a hammer,scissors, a cardboard box, a plastic stick.
