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20 Cards in this Set
- Front
- Back
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Types of Forces |
thrust, drag, lift, weight gravity, tension, electrical, magnetic |
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A force can change motion of a moving object in |
speed, shape, direction |
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forces are balanced |
if constant speed or stationery |
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distance on v-t graph |
area under it |
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energy |
ability to do work |
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work done |
wd = f x d (Nm or J) |
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GPE |
mgh |
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KE |
1/2 m v ^2 |
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Energy types |
KE, GPE, light, Elastic PE, sound, thermal, Chemical PE, Electric, Nuclear |
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Sankey Diagram |
width represents amount of energy |
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conservation of energy |
energy cannot be created nor destroyed, only transferred into different types |
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In no air resistance, loss in GPE = gain in KE |
mgh=mv^2 / 2 v=root(2gh) |
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Constants, spring |
WD = 1/2 * Fx f = max force (n) x = extension at force (m)
Spring -> f=kx k=f/x = n/m Therefore WD=1/2 * kx^2 |
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Efficiency |
(useful energy out/total energy in x 100)% (useful power put/total power in x 100)%
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Power |
rate of doing work P = WD/t = j/s = watts Electrical = IV P = WD/t = Fxd/t = Fv |
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Machine |
something that makes it easier to move a load |
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mechanical advantage |
how much easier it is to move a load using a machine than without (i.e. x times easier) MA = Load / Effort = N |
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Velocity Ratio |
Distance moved by effort / Distance moved by load #Pulleys... |
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Efficiency 2 |
MA / VR |
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NB when calculating speed |
no air resistance change in height |
