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ch. 8 vocab
ch. 8 vocab science
| Question | Answer |
|---|---|
| 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 o express energy; equivalent to the amount of work done by a force if 1 Newton. |
| power | a rate that measures the rate at which work is done or energy is transformed |
| watt | the unit used to express power; equivalent to joules per second |
| machine | a device that helps do work by either overcoming a force of changing the direction of the applied force. |
| work input | the work done by a machine; the product of the output force and the distance through which the force is exerted. |
| work output | the work done on a machine; the product of the input force and the distance through |
| mechanical advantage | a number that times how many times a machine multiplies force. |
| mechanical efficiency | a quantity, usually as a percentage, that measures the ratio of work output to work input; it can be calculated by dividing work output by work input. |
| lever | a simple machine that consists of a bar that pivots at a fixed point called a fulcrum. |
| wheel and axle | a simple machine consisting of tow circular objects of two different sized' the wheel is the larger of the two circular objects. |
| inclined plane | a simple machine that is a straight, slanted surface, which facilitates the raising of loads; a ramp. |
| wedge | a simple machine that is made op 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. |