Posted by **Kris** on Sunday, October 17, 2010 at 5:12pm.

The volume of a cone of radius r and height h is given by V=(1/3)pir^2h. If the radius and the height both increase at a constant rate of 2cm/s at which rate in cubic cm/s is the volume increasing when the height is 8cm and the radius is 6cm.

So The answer is 108 pi.

Here's what I did. I thought that dr/dt=2 and dh/dt=2 looking for dv/dt when h=8 and r=6

so dv/dt=(pi/3)*36*2 + (2pi/3)*6*8*2

I got 88pi....that is wrong....what did I do wrong :'(

Thanks

## Answer This Question

## Related Questions

- Calculus HARD NEED HELP - The volume of a cone of radius r and height h is given...
- Calculus - The volume of a cone of a radius r and height h is given by V=(3.14/3...
- Calculus - The volume of a cone of radius r and height h is given by V=1/3pir^2h...
- calc-related rates - "The volume of a cone of radius r and height h is given by ...
- calculus help please - At the instant when the radius of a cone is 3 inches, the...
- calculus - At the instant when the radius of a cone is 3 inches, the volume of ...
- AP calculus AB - At the instant when the radius of a cone is 3 inches, the ...
- calculus inverted cone - A container in the shape of an inverted cone has ...
- calculus - The radius of a cone increases at the rate of 0.3 inches per minute, ...
- Calculus AB - The volume V or a cone (V = 1/3 π rē h) is increasing at a ...

More Related Questions