A cylindrical water tank with its circular base parallel to the ground is being filled at the rate of 1 cubic feet per minute. The radius of the tank is 2 feet. How fast is the level of the water in the tank rising when the tank is half full?

Question

ddcamp · Answer

If the radius of the tank is 2 feet, then the cross sectional area is 4pi feet². When a volume of 1 cubic foot is added we get:
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The rate at which the water is rising is 1/4pi ft per cubic foot of water added.
Since the water is being added at a rate of one cubic foot per minute, can say that the water is rising at a rate of 1/4pi ft per minute.