SOLUTION: A long straight river, 100 meters wide, is flowing at 1 meter per sec. A pollutant is entering the river at a consistent rate from one of its banks. As the pollutant disperses in t

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Question 1186141: A long straight river, 100 meters wide, is flowing at 1 meter per sec. A pollutant is entering the river at a consistent rate from one of its banks. As the pollutant disperses in the water, it forms a plume that is modeled by the equation y= the sqare root of x.
How wide is the plume at 121 meters?
How wide is it at 400 meters?
How far down from the river source does the pollutant plume reach halfway across the river?
How far down the river does the plume reach the other side?
Answer by ikleyn(52848) About Me  (Show Source):
You can put this solution on YOUR website!
.
(a)  How wide is the plume at 121 meters?

     Substitute the value of 121 m into the formula instead of x and calculate y.



(b)  How wide is it at 400 meters?

     Substitute the value of 400 m into the formula instead of x and calculate y.




(c)  How far down from the river source does the pollutant plume reach halfway across the river?

     Should be  50 = sqrt(x).

     Square both sides and get the ANSWER:  x = 2500 meters = 2.5 kilometers.



(d)  How far down the river does the plume reach the other side?

     Should be  100 = sqrt(x).

     Square both sides and get the ANSWER:  x = 10,000 meters = 10 kilometers.

I answered all your questions.