There are six simple machines. They make it easier for us to do work. A wheel pulley is one of the six simple machines. A pulley is a wheel with a rope wrapped around it. The wheel has a groove around the edge to hold the rope in place. You can attach one end of the rope to a heavy object that you want to lift. You will pull on the other end of the rope to lift the heavy object. Pulleys make work easier by changing the direction of the force needed to do work. It is hard to lift a heavy object up into the air. It is easier to pull the same object down to the ground. This is because of the force of gravity. Gravity is the force that pulls objects down to the Earth. Gravity helps to make work easier when you use a pulley. You can also use more than one pulley at a time to make the work even easier. The weight will feel lighter with each pulley that you use. If you use two .....