Question 1147471
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<pre>

Find the velocity (the speed) as the derivative of the position function over time


    v(t) = {{{(dx)/(dt)}}} = 4t - 12.


Equate it to zero and find the time moment when the speed is zero :


    4t - 12 = 0,


which gives you the answer for unknown time


     t = {{{12/4}}} = 3  units of time.    <U>ANSWER</U>
</pre>

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