VELOCITY (Speed)
- Speed is a measure of how fast an object is moving.
- The technical definition of speed is that it is the rate of change of an object's position with time.
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Definition
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Units:
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Average Velocity
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Instantaneous Velocity
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- The symbol v, short for v(t), represent an object's speed at a single moment of time.
- The average speed can be thought of as the time average of an object's instantaneous speed in the interval between two different times.
- When an object's speed is constant then the object's instantaneous speed and average speed are identical. Moreover,
Comparsion of the Average and Instantaneous Velocity QTMovie (168K)
An object oscillates about the origin with increasing amplitude. Shown is the object's instantaneous velocity as a function of time and the object's average speed between t = 0 and t.
Typical Values of Velocity Table
Many Tags for Velocity
Calculus Relationship
| An object's instantaneous velocity function v(t) is the derivative of the object's position function x(t) with respect to time. |
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Space -Time Plot
| The velocity of an object at some moment of time is the slope the object's position function x(t) at that moment.
The tangent of an object's world line -- the space-time curve of the object's location as a function of time -- is equal to the object's velocity at the location of the tangent. |
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