19 terms

Science Chapter 7 vocal

The science of designing artificial replacements (protheses) for parts of the human body that are not working properly
compound machine
A combination of two or more simple machines.
The ratio of the useful work put out by a machine to the work put into that machine; efficiency is always less than 100 percent.
effort arm
The part of a lever on which an effort force (Fe) is applied.
effort force
The force applied to a machine when a machine is used to do work.
The fixed point around which a lever pivots.
ideal machine
A machine in which work input equals work output; such as a "perfect" machine would be frictionless and 100 percent efficient.
inclined plane
A simple machine consisting of a sloping surface (ramp) used to raise objects.
A simple machine consisting of a bar that is free to pivot (rotate) around a fixed point (fulcrum).
A device that makes work easier by changing the size of the force applied to it and/or the direction of that force
mechanical advantage
The number of times a machine multiplies the effort force applied to it.
The measure of the amount of work done in a specific amount of time; power is measured in watts and equals 1 joule/second.
A simple machine consisting of a grooved wheel with a rope or a chain running along the groove.
resistance arm
The part of a lever that exerts the resistance force (Fr)
resistance force
The force exerted by a machine to overcome resistance to gravity and friction.
A simple machine consisting of a special type of inclined plane wrapped in a spiral around a cylindrical post.
simple machine
A device that accomplishes work with one movement. The lever, pulley, wheel and axle, inclined plane, screw, and wedge are all simple machines.
A simple machine consisting of a moving inclined plane with one or two sloping sides; examples are knives and chisels.
wheel and axle
A simple machine consisting of two different-sized wheels that rotate together, such as a doorknob or wheel-handled faucet.