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1D motion
motion forward or backward, up or down, left or right
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frame of reference
a coordinate system for specifying the precise location of objects in space
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displacement
the change in position of an object
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positive/negative direction
- positive: up/right
- negative: down/left
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average velocity
total displacement divided by the time interval during which the displacement occurred
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instantaneous velocity
the velocity of an object at some instant (or specific point in its path)
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velocity vs. speed
velocity gives a direction, is a vector whereas speed is a scalar
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position vs. time graph slope
- slope is the velocity
- steeper slope means greater speed
- straight line is constant velocity
- horizontal line is at rest
- positive value means positive direction, negative value means negative direction
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acceleration
the rate of change of velocity
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acceleration with constant velocity
0
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velocity vs. time graph
- shows acceleration
- object is at rest when the velocity is 0
- upward slope: speed increasing
- horizontal slope: constant velocity, no acceleration
- downward slope: speed decreasing
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positive velocity and acceleration
speeding up
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negative velocity and acceleration
speeding up
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positive velocity and negative acceleration
slowing down
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negative velocity and positive acceleration
slowing down
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0 velocity and 0 acceleration
at rest
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constant acceleration
velocity increases by the same amount during each interval; displacement for each time interval increases by the same amount
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free fall
motion of an object falling with a constant acceleration
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motion
natural event that involves a change in the position or location of something
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3 physical descriptions that describe motion
- displacement: change in position
- velocity: rate at which the displacement changes
- acceleration: rate at which the velocity changes
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vector
- physical quantity with magnitude and direction
- e.g. velocity, displacement, acceleration, force
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sector
- has magnitude only
- e.g. speed, mass, temperature, time
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acceleration vs. time graph
- horizontal line is constant acceleration
- sign of acceleration is the same as the sign of velocity
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free fall constant
-9.81m/s2
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