Levers
![Picture](/uploads/2/8/5/0/285015/8020663.jpg?251)
Lever
What do you think of when someone mentions a lever? Most people think of see-saws. Although a see-saw is a lever, it only represents a small portion of levers. We still have not answered the most important question - What is a lever? A lever is a simple machine that consists of a rigid bar that pivots around a fixed point called a fulcrum. This bar may be straight or curved. When is use, a lever has both an an effort (applied) force, and a load (resistance force.) Levers are used for many purposes. They are used to pry things open. As shown in the picture above, they can also be used to lift heavy objects. Scissors, doors, and shovels are also levers. There are three classes of levers:
- First-Class levers
- Second-Class levers
- Third-Class levers