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17 Cards in this Set
- Front
- Back
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Simple Machines
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- levers
- Ramps (inclined planes) - pulleys |
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Perfect machines
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100 % efficient
Win=Wount Win- work i do on machine Wout- work done on object |
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Win=Wout
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Findin=Foutdout
Fin- small din- big Fout- big dout- small Tradeoff between F and d |
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Mechanical Advantage
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- factor that a machine multiplies force
MechAdv- 5 5 times more force than put in |
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Efficiency
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Measure of how much energy gets wasted by the machine
Bigger machine- wasting less Eff= Win/Wout |
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Energy Source Idea
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- You can't get something from nothing, everything < 100 % efficient
- hidden costs - plastic |
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Circular Motion
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Motion in a circular pattern
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Rotation
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Turning around an internal axis (spinning)
Day and night |
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Revoluton
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Moving around an external axis (orbitting)
Year (365 rotations) |
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Rotational speed
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rate of turning- same for all parts of a rigid object
rot/s, rev/min (RPM) Trips around per time |
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Tangential (linear) Speed
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Rate of covering distance ms. proportionl to the distance from axis
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Turning
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-Turning is acceleration!
Force requires to turn always pushes inward. |
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Centripetal Force
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"Center directed"
Inward force that causes turning. - turning tighter and at a faster speed requires Fcentrip |
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Centrifugal Force
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"Center Fleeing"
- does not exist -Illusion created by Inertia |
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Simulated Gravity
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1g- sensation of normal gravity
2-3 RPM- can adapt - antything above can create dizziness |
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Center of Mass
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(cm)
average of mass in an object - follows the "expected trajectory" - serves as a natural axis of rotation - can pretend that alk the gravity force acting on an objects acts at the cm - An object will fall over if its center of mass extends beyond its base of support |
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Increase Stability
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Make base of support bigger
- lower center of mass |
