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Physical Science
Chapter 8 Test
Question | Answer |
---|---|
Block and Tackle | Multiple pulley system. Mechanical advantage for pulleys in a block and tackle = numbers of pulleys used |
Compound Machine | a device that combines two or more simple machines |
First Class Lever | Lever in which the fulcrum is in the middle |
Fixed Pulley | a pulley attached to something that does not move. |
Fulcrum | The fixed point around which a lever pivots |
Ideal Machine | machine in which work input equals work output; no friction; 100% efficiency |
Input Force | a unit of work equal to one newton-meter |
Kinetic Energy | the energy an object has due to its motion |
Lever | a rigid bar that is free to move around a fixed point |
Machine | Machine a device that makes work easier |
Mechanical Advantage | the number of times the force exerted on a machine is multiplied by the machine |
Mechanical Efficiency | a quantity, usually expressed as a percentage, that measures the ratio of work output to work input in a machine |
Movable Pulley | a pulley in which one end of the rope is fixed and the wheel is free to move |
Output Force | the force that is exerted by a machine |
Power | the rate at which work is done |
Pulley | a simple machine that consists of a rope that fits into a groove in a wheel |
Radius | The distance from the center of a circle to a point on the circle |
Screw | a simple machine that consists of an inclined plane wrapped around a cylinder |
Second Class Lever | input force is between the fulcrum and the load |
Watt | unit for power |
Wedge | a V-shaped object whose sides are two inclined planes sloped toward each other |
Wheel and Axle | a simple machine that has a center rod attached to a wheel |
Work | force exerted on an object that causes it to move |
Work Input | the work done "ON" a machine |
Work Output | work done "BY" the machine |