Results 1 to 2 of 2

Math Help - Cylinders

  1. #1
    Newbie
    Joined
    Dec 2006
    Posts
    17

    Post Cylinders

    Water bubbles up at a rate of 1 cm^3/s, forimging a circular pond of depth 0.5 cm in his yard. How quickly is the surface area of the pond covering his lawn?


    how would i find r to plug into the volume equation?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by Tascja View Post
    Water bubbles up at a rate of 1 cm^3/s, forimging a circular pond of depth 0.5 cm in his yard. How quickly is the surface area of the pond covering his lawn?


    how would i find r to plug into the volume equation?
    The volume of the pond is:

    <br />
V=A d<br />

    where d is the depth of the water, and A is the surface area of the pond.

    So the rate of change of volume is:

    <br />
\frac{dV}{dt}=\frac{dA}{dt}\ d<br />

    but we are told that this is 1\ \rm{ cm^2/s}, and as d=0.5 \mbox{ cm} we have:

    \frac{dA}{dt}=1/d=2\ \rm{cm^2/s}

    RonL
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Intersection of Three cylinders
    Posted in the Calculus Forum
    Replies: 1
    Last Post: November 16th 2011, 06:21 PM
  2. Question about Cylinders
    Posted in the Geometry Forum
    Replies: 3
    Last Post: March 3rd 2011, 03:13 PM
  3. volumes of cylinders
    Posted in the Geometry Forum
    Replies: 5
    Last Post: August 16th 2010, 09:48 AM
  4. collection of cylinders
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: November 2nd 2009, 05:02 PM
  5. About cylinders
    Posted in the Calculus Forum
    Replies: 0
    Last Post: September 6th 2008, 07:43 PM

Search Tags


/mathhelpforum @mathhelpforum