| A | B |
|---|
| Compound machine | a device made up of a combination of simple machines. |
| Input force | the force exerted on a machine. |
| Fixed pulley | a pulley that does not move; it only changes the direction of the effort force. |
| Friction | the resistance to motion of one object rubbing against another |
| Fulcrum | a fixed point around which a lever rotates. |
| Inclined plane | a sloping surface, like a ramp, that reduces the amount of force required to lift an object. |
| Lever | a rigid bar or board that is free to move around a fixed point called a fulcrum. |
| Movable pulley | a pulley that moves; it changes the force and distance of the effort force. |
| Pulley | a grooved wheel with a rope or cable wrapped around the groove. |
| Output force | the force exerted by a machine. |
| Screw | an inclined plane wrapped around a post or cylinder. |
| Simple machine | a device that makes work easier by changing the force, distance, or direction of the effort force. |
| Spring scale | a tool used to measure the weight of an object or the force on an object in units of Newtons or pounds. |
| Wedge | two inclined planes back-to-back, sometimes called an inclined plane that moves. |
| Wheel and axle | two circular objects of different sizes that are attached and rotate together. |
| Work | force exerted on an object that causes that object to move some distance. |
| Efficiency | a comparison between the input work and the output work of a simple machine. |
