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14 Cards in this Set
- Front
- Back
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Force |
any push or pull, measured in newtons |
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Work |
Work is done when an object is moved through a distance in the direction of the applied force. |
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What is the WORK formula? |
work=force X distance W=Fd |
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joule |
unit for work equal to a newton-meter(yes, this is the same unit for energy!) |
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Power |
measure of the amount of work done in a certain time |
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What is the POWER formula? |
power=W/t |
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watt (W) |
unit for power |
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simple machine |
device that makes work easier |
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mechanical advantage |
measured as the number of times a machine multiplies the force applied to the machine.A larger mechanical advantage means the machine does more of the work. Mechanical Advantage = Resistance Force/Effort Force |
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efficiency |
ratio of work output to work input how much useful work is done by a machine compared to the work put into the machine. Efficiency is expressed as a percentage. Efficiency can never be 100% because of friction. |
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What are the Purposes of simple machines? |
1. to change the effort needed (mechanical advantage) 2. to change the direction or distance through which the force is applied 3. to change the speed at which the resistance moves 4. or a combination of these. |
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What are the 6 simple machines? |
lever pulley wheel & axle inclined plane screw wedge |
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How much work is done on a 16 N sack of potatoes when you lift the sack 1.5m? |
W=F X d W=16N X 1.5m W=24J |
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A 50N girl climbs a 3m flight of stairs in 3 seconds. How much work is done? How much power is produced? |
W=FXd W=50N X 3m W=150J P=W/t P=150J/3s P=50W |
