All terms in this list:

inclined planes: wedges, screws, and ramps

lever: A rigid piece which is capable of turning about one point, or axis (the fulcrum), and in which are two or more other points where forces are applied; — used for transmitting and modifying force and motion. Specifically, a bar of metal, wood or other rig

fulcrum: The support about which a lever pivots.

effort arm: portion between the fulcrum and the effort applied in a lever

effort force: used to move an object over distances

1st class levers: the fulcrum is between the resistance and the effort forces

2nd class levers: the resistance is between the fulcrum and the effort force

3rd class levers: the effort force is between the fulcrum and the resistance

wheels: are modified levers

pulleys: a grooved wheel that turns on an axle

block & tackle: a system of fixed and movable pulleys

mechanical efficientcy: the output work to the work or energy put into a process

resistance arm: the side of the lever that carries the load

conservation law: states that is something is conserved; that is, something remains constant under certain conditions

air resistance: The action of friction that slows something moving through air.

friction: The rubbing of one object or surface against another.

conservative force: the energy expended when doing work against them is stored as potential energy and can be regained as kinetic energy

escape speed: the minimum speed that an object of mass m requires to leave a larger object of mass M so that mass m can not return due to gravitational attraction alone

central force: a conservative force between two bodies always pushes or pull along the line joining the centers of the bodies

machine: A mechanical or electrical device that performs or assists in the performance of human tasks, or is used for amusement (like a pinball machine). a device that changes the magnitude or direction of a applied force