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Mission KC8 Pos'n-Time and Vel-Time Data

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 The Question

The position-time data sets below represent the motion of four objects. Which data set depicts the largest speed? Ignore all + and - signs; compare magnitude only. (OR which is moving, yet with the smallest speed?)

 Define Help

Definition of Speed:
The speed of a moving object refers to how fast the object is moving. It is the distance traveled per unit of time.

 Think About It

Data tell a story - in this case, a story about how the position of the moving object is changing at 1-second (or even 0.5-second) intervals. The object with the greatest speed is the one that has the greatest distance/time ratio (see Formula Frenzy section). The moving object with the smallest speed is the one that has the smallest distance/time ratio (other than 0 m/s). Perhaps the easiest way to determine the average speed is to inspect the first and the last row of the data table. Determine the distance traveled from the initial position and the final position. Dividing this distance by the overall change in time will yield the average speed value.

 Formula Fix

The average speed of an object can be determined as the ratio of the overall distance traveled per time of travel:
 
average speed = distance / time

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