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PS Ch5
Vocabulary
Term | Definition |
---|---|
Work | Transfer of energy that occurs when a force makes an object move; measured in joules. |
Power | Amount of work done, or the amount of energy transferred, divided by the time required to do the work or transfer the energy; measured in watts. |
Machine | Device that makes doing work easier by increasing the force applied to an object, changing the direction of an applied force, or increasing the distance over which a force can be applied. |
Input Force | The force that is applied to the machine. |
Output Force | The force applied by the machine. |
Mechanical Advantage | Ratio of the output force exerted by a machine to the input force applied to the machine. |
Efficiency | Ratio of the output work done done by the machine to the input work done on the machine, expressed as a percentage. |
Simple Machine | Machine that does work with only one movement -- lever, pulley, wheel and axle, inclined plane, screw, and wedge. |
Lever | Simple machine consisting of a bar free to pivot about a fixed point called the fulcrum. |
Pulley | Simple machine that consists of a grooved wheel with a rope, chain, or cable running along the groove; can be either fixed or moveable. |
Wheel and Axle | Simple machine that consists of a shaft or axle attached to the center of a larger wheel, so that the shaft and the wheel rotate together. |
Inclined Plane | Simple machine that consists of a sloping surface, such as a ramp, that reduces the amount of force needed to lift something by increasing the distance over which the force is applied. |
Screw | Simple machine that consists of an inclined plane wrapped in a spiral around a cylinder post. |
Wedge | Simple machine that is an inclined plane with one or two sloping sides. |
Compound Machine | Machine that is a combination of two or more simple machines. |