Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Volume or area?

  1. Jan 22, 2006 #1
    Does pi/4(d^2) equal volume or area? OR neitheR?
     
  2. jcsd
  3. Jan 22, 2006 #2
    Neither. I have no idea what that is supposed to represent. Of course, I'm assuming you're talking about a sphere(based on the presence of pi, and your reference to both volume and area), but you did not specify.
     
  4. Jan 23, 2006 #3

    Pengwuino

    User Avatar
    Gold Member

    It represents an area but what area? I don't know, certainly no readily identifiable geometric shape.
     
  5. Jan 23, 2006 #4

    Well, is it
    [tex]
    \frac{\pi}{4 d^2}
    [/tex]
    or
    [tex]
    \frac{\pi}{4} d^2
    [/tex]

    Assuming d is in meters, the first (how i read it) is not an area, the second(how i assume you read it, and i did not think of until you posted) is. The second is the area of a circle (where [tex] r= \frac{d}{2}[/tex]), if d is a diameter.

    @Zenaide: In the future you need to provide more information with a question. A single sentence will almost never be enough information for us to say anything definitive.
     
  6. Jan 23, 2006 #5
    [tex]
    \frac{\pi}{4} d^2
    [/tex]
    Okay That ^^^^^ is what I meant.... I had a sheet of equations but I don't have it and I can't find the equation for what that series of things equal... and I was using d as a diameter for a water tank.... SO I'm assuming the water tank is a cylnder. becuase it has a height and a diameter.
     
  7. Jan 23, 2006 #6

    Then that would be the cross sectional area. The volume would be
    [tex]
    V = \frac{\pi}{4} d^2 h
    [/tex]

    where h is the height in meters.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook