1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Calculate Weight

  1. Jul 13, 2004 #1
    Hi,

    I am a bit new to this area of physics.

    My question:

    1) How much minimum weight (in milligrams or grams) is required to keep 1 m3 (1 meter cube) of Helium / Hydrogen contained in a container of negligible weight at normal atmospheric pressure (outside pressure).

    This question has been bugging me since my childhood and I am not able to gather an answer for this so long.

    You could also mail me at prasad@pspindia.com which I would appreciate.

    Thanks

    Prasad
     
  2. jcsd
  3. Jul 13, 2004 #2
    This is a common problem in most physics textbooks.

    Essentially, you vector sum the forces acting on the container to 0, since the container is not accelerating (please, no general relativity). There are two forces acting on the container: the force of gravity [tex]F_g = mg[/tex] and the buoyancy force [tex]F_B = \rho V g[/tex]. Since they must vector cancel, set the two forces equal and solve for the mass m.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook