A racing car goes from 30 m/s to 50 m/s over a 5.0-s interval. If the acceleration is constant, how far does it go during this time?
Solution
Restating the problem. The question asks for a distance traveled during a time interval: What is |Δx| during a particular Δt of 5 s if v changes from v1 = 30 m/s to v2 = 50 m/s during this time interval?
What we know/what we don't.
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Choice of approach.
(1) Because the acceleration is constant, the average velocity meets the condition that 
, which we can use to find v
. (2) Once we know v
, we can use the definition of average velocity 
to find Δx.
The mathematical solution.
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 Related homework: Problems 2-35, 2-36, and 2-37. |