Download Technology: Shaping Our World Chapter 8. Machines—Terms and

Technology: Shaping Our World
Chapter 8. Machines—Terms and Definitions
Friction: a force that acts like a brake on moving objects.
Gear: a rotating wheel-like object with teeth around its rim; they are used to transmit force to other
gears with matching teeth.
Hydraulics: the study and technology of the actions and reaction of liquids at rest and in motion.
Inclined plane: a simple machine in the form of a sloping surface or ramp, used to move a load
from one level to another.
Lever: a simple machine, consisting of a bar and fulcrum (pivot point), that can be used to increase
force or decrease effort needed to move a load.
Linkage: a system of levers used to transmit motion.
Machine: a device that does some kind of work by changing or transmitting energy.
Mechanical advantage: in a simple machine, the ability to move a large resistance by applying a
small effort.
Mechanism: a way of changing one kind of effort into another kind of effort.
Moment: the turning force acting upon a lever, determined by the effort times the distance of the
effort from the fulcrum.
Pneumatics: the study and technology of the characteristics of gases.
Power: the rate at which work is done or the rate at which energy is converted from one form to
another or transferred from one place to another.
Pressure: the effort applied to a given area.
Pulley: a simple machine in the form of a wheel with a groove around its rim to accept a rope, chain,
or belt; it is used to lift heavy objects.
Screw: a simple machine that is an inclined plane wrapped in the form of a cylinder.
Torque: a measure of turning effort.
Wedge: a simple machine that consists of two inclined planes placed back-to-back.
Wheel and axle: a simple machine that is a special kind of lever; effort applied to the outer edge of
the wheel is transmitted through the axle.
Work: measurement of the amount of effort needed to change one kind of energy into another; the
result of a force applied on an object and the object’s movement in the direction of the force applied
on the object.
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