1. Simple Machines All machines are made from the six simple machines: lever, inclined plane, wedge, screw, wheel and axle, and pulley

2. Levers Consist of a bar that pivots at a fixed point (fulcrum) Used to apply a force to a load There are three classes First class levers: The fulcrum is between the input force and the load Always change the direction of the input force Can be used to increase force or to increase distance

3. Levers Continued Second class levers: The load is between the fulcrum and the input force. The direction of the input force does not change, but allows you to apply less force The input force must be exerted over a greater distance. Third class levers: The input force is between the fulcrum and the load. The direction of the input force does not change or increase. The output force is always less than the input force.

4. Inclined Planes and Wedges Inclined planes: A straight, slanted surface A smaller input force is exerted over a longer distance The longer the inclined plane, the greater the mechanical advantage. Wedges: A double inclined plane; it applies a force on an object The input force is applied over a greater distance causing it to be less than the output force. The greater the distance you move a wedge, the greater the force it applies on an object.

5. Screws & Wheel and Axle Screws: Inclined plane wrapped in a spiral; used as fasteners A small input force is exerted over a large distance, while the screw exerts a large output force over a small distance Wheel and Axle: Two circular objects of different sizes; the larger one is the wheel and the smaller is the axle A small input force applied to the wheel results in a larger output force by the axle.

6. Pulleys and Compound Machines Pulley: A grooved wheel that holds a rope or cable Two types fixed and movable Fixed Pulleys change the direction of the force Movable Pulleys increase the force, but does not change the direction Compound Machines: Machines made of two or more simple machines Friction must be reduced for these simple machines by using lubrication