Posted by **Vivi** on Wednesday, February 13, 2013 at 1:54am.

Water is draining at a rate of 2 cubic feet per minute from the bottom of a conically shaped storage tank of overall height 6 feet and radius 2 feet . How fast is the height of water in the tank changing when 8 cubic feet of water remain the the tank? Include appropraite units in your answer. (Note: The volume of a cone is given by V=(1/3)(pi)(r^2)(h)) Your answer may be expressed in terms of pi.

- Calculus -
**Steve**, Wednesday, February 13, 2013 at 1:10pm
when the water is y ft deep, the radius of the surface is y/3.

v = 1/3 pi r^2 h = 1/2 pi (y/3)^2 * y = pi/18 y^3

so, y = (18v/pi)^(1/3)

dy/dt = 1/3 * (18v/pi)^(-2/3) * 18/pi

= 1/3 * 18/pi * (pi/18*8)^(2/3)

= 4∛(2/(3pi))

## Answer this Question

## Related Questions

- AP calculus AB - Water pours out of a conical tank of height 10 feet and radius ...
- Calculus - A conical tank has a height that is always 3 times its radius. If ...
- Calculus - Water is leaking from the bottom of a tank in the shape of an ...
- Please check my calculus - A conical tank has a height that is always 3 times ...
- related rates problems - Water pours out of a conical tank of height 10 feet and...
- AP calculus - The base of a cone-shaped tank is a circle of radius 5 feet, and ...
- Calculus - A water tank is shaped like an inverted right circular cone with a ...
- calculus - Water is flowing freely from the bottom of a conical tank which is 12...
- math - a vessel comtaining water has the shape of an inverted circular cone of ...
- calculus-rate problem - A conical tank (with vertex down) is 10 feet acros the ...

More Related Questions