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Homework Help: Finding surface area of a sphere

  1. Apr 4, 2006 #1
    Can someone tell me how to find the surface area of a sphere when given the Area? :confused: thanks
  2. jcsd
  3. Apr 4, 2006 #2


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    You mean "given the volume"? Do you know the formulas for the surface area of a sphere, given its radius? What about for the volume, given its radius?
  4. Apr 5, 2006 #3


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    I think you means volume, not area, right?
    The volume of a sphere can be calculated by:
    [tex]V = \frac{4}{3} \pi r ^ 3[/tex]
    where r is its radius.
    Now given its volume, can you find its radius?
    And after finding its radius, can you find its surface area?
    Hint: The surface area is:
    [tex]A = 4 \pi r ^ 2[/tex]
    where r is the sphere's radius.
    Can you go from here? :)
  5. Apr 5, 2006 #4


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    Well, actually, the volume of the sphere is 0 in any possible metric space, in which we can define such an object.

    So linking 0 with [itex] 4\pi r^2 [/itex] is quite easy, if you assume the sphere to have a zero radius.


    P.S. Most of this post is not a joke.
  6. Apr 5, 2006 #5
    thank you all!
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