A machine is an object that helps move things easier. Machines can change force and distance. A machine can also change the direction of a force. Force is the power or energy needed to move an object.
A lever is a simple machine. It is used to move or lift an object. A lever can be a board or a stiff bar. It is supported, or helped, by another object. The supporting object is called a fulcrum or pivot.
A fulcrum can be put at different places on the lever. Depending on where the fulcrum is set, the load will move different distances.
An object that a lever moves is called the load. The closer the load is to the fulcrum, the easier it is to move. When you push down on one end of a lever, the other end moves up. If there is a load on the other end, it moves up, too! A lever can move things higher or lift them easier.
There are three classes of levers. A class 1 lever has the fulcrum between the load and the force. A seesaw and hammer are good examples of class one levers. A class 2 lever has the load between the force and the fulcrum. A wheelbarrow and stapler are good examples. In a class 3 lever the force is between the fulcrum and the load like tweezers or tongs.