Results 1 to 2 of 2

Math Help - Surface Area And Volumes

  1. #1
    Newbie
    Joined
    Aug 2006
    Posts
    11

    Question Surface Area And Volumes

    if the radius of cylinder is increased by 10%,how much will the length be decreased so that volume remains the same?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    10,212
    Thanks
    419
    Awards
    1
    Quote Originally Posted by anjana View Post
    if the radius of cylinder is increased by 10%,how much will the length be decreased so that volume remains the same?
    V = \pi r^2 L

    So if we increase r by 10% r \to \frac{11r}{10}

    So what is our new L'?

    V = \pi r^2 L = \pi \left ( \frac{11r}{10} \right )^2 L'

    \pi r^2 L = \pi \frac{121}{100} r^2 L'

    Cancelling the common \pi r^2:
    L = \frac{121}{100} L'

    L' = \frac{100}{121} L

    L' = 0.826 L

    or we have reduced the length to about 82.6% of it's original value.

    -Dan
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Surface areas and Volumes
    Posted in the Math Topics Forum
    Replies: 1
    Last Post: October 7th 2008, 01:40 AM
  2. Help with surface area, volumes and measures
    Posted in the Calculus Forum
    Replies: 1
    Last Post: March 16th 2008, 08:58 AM
  3. surface areas and volumes
    Posted in the Geometry Forum
    Replies: 1
    Last Post: September 20th 2006, 11:46 AM
  4. surface areas and volumes
    Posted in the Geometry Forum
    Replies: 1
    Last Post: September 20th 2006, 11:27 AM
  5. surface areas and volumes
    Posted in the Geometry Forum
    Replies: 1
    Last Post: September 20th 2006, 11:24 AM

Search Tags


/mathhelpforum @mathhelpforum