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: Mass of helium

  1. Feb 4, 2007 #1
    1. The problem statement, all variables and given/known data

    A balloon 20 m in diameter is filled with helium at a gauge pressure of 2.0 atm. A man is standing in a basket suspended from the bottom of the balloon. A restraining cable attached to the basket keeps the balloon from rising. The balloon (not including the gas it contains), the basket and the man have a combined mass of 150 kg. the temperature is 24oC that day and the barometer reads 760 mm Hg.

    What is the mass of helium?

    2. Relevant equations

    pV = nRT

    3. The attempt at a solution

    (3 atm x 101325 Pa/atm)(4/3*pi*(10^3)) = (m/0.004)(8.314)(297.15)
    m = 2061 kg

    But the correct ans is 2050 kg. Anyone pls help? thanks
    Last edited: Feb 4, 2007
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted