<PRE><B>Question 1061875</B>
he starts off at 3500 feet at 11:05 am.
he descends to 1000 feet5 at 11:10 am.


he has descended 2500 feet in 5 minutes.


divide 2500 by 5 and you get an average descent of 500 feet per minute.


the rate of change would be -500 feet per minute.


you can use the general equaion of rate * time = distance.


the time is 5 minutes.


the distance is -2500 feet.


rate * time = distance becomes rate * 5 = -2500


solve for rate to get rate = -2500 / 5 = -500 feet per minute.


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