| A | B |
|---|
| pulley | A simple machine consisting essentially of a wheel with a grooved rim in which a pulled rope or chain can run to change the direction of the pull and thereby lift a load. |
| wheel and axle | A simple machine consisting of an axle to which a wheel is fastened so that torque applied to the wheel winds a rope or chain onto the axle, yielding a mechanical advantage equal to the ratio of the diameter of the wheel to that of the axle. |
| wedge | A simple machine that is a piece of material, such as metal or wood, thick at one edge and tapered to a thin edge at the other for insertion in a narrow crevice, used for splitting, tightening, securing, or levering. |
| screw | A simple machine of the inclined-plane type consisting of a spirally threaded cylindrical rod that engages with a similarly threaded hole, used to fasten two pieces of material together. |
| inclined plane | A simple machine for elevating objects; consists of plane surface that makes an acute angle with the horizontal. |
| gears | A simple machine, such as a wheel or cylinder, that meshes with another toothed part to transmit motion or to change speed or direction. |
| lever | A simple machine consisting of a rigid bar pivoted on a fixed point and used to transmit force, as in raising or moving a weight at one end by pushing down on the other. |
| simple machine | A Machine that has few or no moving parts. |
| complex machine | A machine that uses a combination or series of simple machine parts |
| compound machine | A machine that consists of two or more simple machines. |
| load | A weight or mass that is an external mechanical resistance against which a machine acts. |
| effort | The force or energy that is applied to a machine for the accomplishment of useful work. |
| work | Physical or mental effort or activity directed toward the production or accomplishment of something. |
| machine | A device that applies force, changes the direction of a force, or changes the strength of a force, in order to perform a task, generally involving work done on a load. |
