Question 1120315
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Don't get too lost in the forest because of the trees....<br>
The statement of the problem gives you the answer.  The speed is constant at 6 units per second; so the rate of change of its distance from ANY point at ANY time is 6 units per second.<br>
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sorry -- I misread the problem as motion in one dimension.<br>
See the correct solution from tutor @ikleyn.