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!

Homework Help: Helium Balloon payload

  1. Dec 13, 2008 #1
    1. The problem statement, all variables and given/known data
    a) a light balloon is filled with 400m^3 of helium at 0 degree C, the ballon can lift a payload of what mass?
    b) what if? the density of hydrogen is nearly 1/2 the density of helium. what load can the balloon lift if filled with hydrogen?

    answer A) 444Kg B) 480Kg

    I have been trying various equations with buoyant force but none of them are giving me the answer I need
  2. jcsd
  3. Dec 13, 2008 #2
    The buoyant force is equal to the volume times g times the difference in densities between the two fluids (air and helium, in this case). This means that the mass of the payload will be equal to the volume times the difference in densities.

    In this case, the density of air at 0˚C is 1.29 kg/m^3, and the density of helium is 0.18 kg/m^3, so the difference is 1.11 kg/m^3. This time 400 m^3 is the mass, 444 kg.
  4. Dec 13, 2008 #3
    thanks, I understand now.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook