One kind of lever is the first-class lever. A first-class lever has a fulcrum in the middle. A fulcrum is a object that supports the bar and allows it to turn or pivot. The load goes on the left and when the effort force pushes down on the other side of the seesaw the load goes up.

Pulley

A pulley is a object that can move a another object. One kind of pulley is the movable pulley. A movable pulley is not attached to some fixed object. It moves with the load.

Wedge

• A wedge changes a downward or forward force into a sideways force.

Inclined Planes

• A inclined plane has only one part. One kind of inclined plane is a ramp. You could also call a inclined plane a flat, slanted surface.

Screw

• A screw is a inclined plane twisted into a spiral. A screw has a very sharp blade.

Wheel and Axle

• An example of a wheel and axle is a doorknob. The knob is the wheel and the bar is the axle.