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Chapter 8 Vocabulary
Word | Definition |
---|---|
Work | The transfer of energy to an object by using a force that causes the object to move in the direction of the force. |
Joule | The unit used to express energy,equivalent to the amount of work done by a force of 1N acting through a distance of 1m in the direction of the force. (symbol,J) |
Power | The rate at which work is done or energy is transformed. |
Watt | The unit used to express power, equivalent to joules per second. (symbol,W) |
Machine | A device that helps do work by either overcoming a force or changing the direction of the applied force. |
Work Input | The work done on a machine, the product of the output force and the distance through which the force is exerted. |
Work Output | The work done by a machine, the product of the output force and the distance through which the force is exerted. |
Mechanical Advantage | A number that tells how many times a machine multiplies force. |
Mechanical Efficiency | A quantity, usually expressed as a percentage, that measures the ratio of work output to input. |
Lever | A simple machine that consists of a bar that pivots at a fixed point called a fulcrum. |
Pully | A simple machine that consists of a wheel over which a rope, chain, or a wire passes. |
Wheel and Axle | A simple machine consisting of two circular objects of different sizes. |
Inclined Plane | A simple machine that is a straight, slanted surface, which facilitates the raising of loads. |
Wedge | A simple machine that is made up of two inclined planes and that moves, often used for cutting. |
Screw | A simple machine that consists of an inclined plane wrapped around a cylinder. |
Compound Machine | A machine made of more than one simple machine. |