The base of the fish tank below has a length of 40 inches, a width of 20 inches, and height of 1.5 feet. The tank starts off with a water depth of 7 inches. You then add water to the tank at a constant rate such that the water level increases 1 inch every 2 minutes. Wirte a funcion representing the fish tank's water volume in terms of t minutes.

1 answer

the water surface has a constant area of 800 in^2.

So, every inch of water adds a volume of 800 in^3.

So, after t minutes, the tank holds

v(t) = 7*800 + 800t in^3

You should probably restrict the domain of t so that the tank does not overflow.