There is also a moveable pulley. In this type, the pulley itself is attached to the object so when the object moves, the pulley moves. This kind of pulley increases force as well as direction. Both pulleys help us lift heavy objects but a moveable pulley makes the lifting easier because it increases the effort. You have seen construction workers use pulleys called cranes to lift bricks and steel beams.
Farmers use pulleys to lift bales of hay and bags of grain.
Another modification of a lever is a wheel and axle. A wheel and axle consists of two different-sized wheels put together. The larger one is the wheel and the smaller one, the axle. Turning the axle makes the wheel turn. You use a wheel and axle every time you open a door with a door knob, turn the knob on your radio or television, turn the steering wheel of a car or ride a bicycle.