- Wheels and Levers - GlossaryAxle:
A shaft or rod on which a wheel turns (fixed or free).
Balance:
A condition in which opposing forces exactly balance or equal
each other; state of equilibrium.
Block and Tackle:
A unit made up of several pulleys linked together by ropes.
Cog:
Another term for gear wheel.
Conservation of energy:
Energy can neither be created or destroyed. The energy output of
a machine is equal to the energy input.
Driver:
Wheel or gear that transfers force to other wheels or gears.
Driven gear or wheel:
The wheel or gear that is moved by the force of a driver wheel or
gear.
Effort:
The force (push or pull) that produces an action.
Energy:
Ability to do work.
Force:
A push or pull that makes an object move. Force equals mass
times distance.
Friction:
A force that resists motion between two objects that touch - there
is less friction between smooth surfaces than between rough
surfaces.
Fulcrum:
The supporting point of a lever; also called a pivot.
Gear:
Toothed wheel that transmits motion from one shaft to another.
Gears: (beveled)
Alter direction of motion by 90, e.g. a hand mixer.
Gears: (rack and pinion) Change circular motion to linear (straight) motion. e.g. a steering
column.
Gears: (worm)
Changes direction of motion by 90 and alters speed, e.g. an
electric mixer.
Idler:
A gear that transmits force and motion from one gear to another.
Lever:
A bar that can rest on a pivot or support point called a fulcrum.
Force or effort is applied to one place to move a load at another
place.
Mass and weight:
Mass is the amount of matter that is contained in a body measured
in kilograms. Weight is the attraction of the force of gravity on
that body measured in Newtons. On the Earth, a person whose
mass is 50 kg has a weight of approximately 500 N.
Mesh:
To smoothly interlock the teeth of two or more gear wheels.
Motion:
Change in the position of an object (speed = rate of motion).
Newton:
Newton (N) is the force required to give a one kg mass an
acceleration of one meter per second.
Perpetual Motion:
Endless motion without friction..
Power:
The rate at which work is done. Power is the product of the time
the force acts, the force required and the distance a load is moved.
Pulley:
A wheel with a groove in the rim in which a rope or belt moves.
Resistance:
The force that must be overcome to produce work in a machine also called load.
Shaft:
Another term for axle.
Work:
The result of a force moving an object.