Results 1 to 2 of 2

Math Help - math problem!!

  1. #1
    Newbie
    Joined
    Jun 2008
    Posts
    1

    Lightbulb math problem!!

    using V= TTr2h, find the volume of a cylinder with a diameter of 18 cm and a height of 2.5 cm. round to the nearest tenth..

    a. 70.7 cm3 c. 141.4 cm3
    b. 636.2 cm3 d. 2544.7 cm3


    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member
    Joined
    Jun 2008
    Posts
    175
    The volume of a cylinder is just the area of one of its end (a circle) multiplied by the height. With the area of a circle being given by :

    A = \pi r^2 or by A = \frac{{\pi d^2 }}{4}
    than you volume with by Area by height. ie

    V = \pi r^2 h or V = \frac{{\pi d^2 }}{4}h

    the radius of a circle is just half of its diameter.

    diameter = 18cm therefore radius = 1/2 * 18 = 9cm
    your height is given as 2.5cm

    Therefore you work your volume out as below

    V = \pi  \times 9^2  \times 2.5 = \pi  \times 81 \times 2.5 = 636.17^3

    Accuracy to 1/10th just means to 1 decimal place ie because answer is 636.1725124.... accurate to 1/10th or 1 decimal place will be to round up giving answer as 636.2
    Last edited by Craka; June 8th 2008 at 06:42 AM. Reason: correcting typo
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. GRE Math problem help!
    Posted in the Geometry Forum
    Replies: 1
    Last Post: October 7th 2010, 02:13 PM
  2. help in math problem
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: September 6th 2009, 10:35 AM
  3. Please help with this math problem
    Posted in the Algebra Forum
    Replies: 1
    Last Post: January 30th 2009, 01:18 AM
  4. Please help with this math problem!!!!!please
    Posted in the Algebra Forum
    Replies: 0
    Last Post: November 13th 2008, 02:13 PM
  5. Math Problem Help!
    Posted in the Algebra Forum
    Replies: 1
    Last Post: September 17th 2006, 12:46 PM

Search Tags


/mathhelpforum @mathhelpforum