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Homework Help: What is the Vrms, in m/s, for helium atoms at 4.8 K?

  1. Jan 20, 2016 #1
    1. The problem statement, all variables and given/known data
    What is the Vrms, in meters per second, for helium atoms at 4.8 K? (which is close to the point of liquefaction)

    2. Relevant equations
    Vrms= √(3RT)/(M)

    3. The attempt at a solution
    T= I think its 4.15 Kelvin? based on the point of liquefaction of helium being -269°C
    -unsure about the temperature
    M= I think its 0.004003 Kg based on the molar mass of helium

    Vrms= Sqrt (3*3.1845*4.15)/(0.004003)

    Any help would be greatly appreciated, Ive tried this a million ways and can't seem to figure it out,
    Thank You!!
  2. jcsd
  3. Jan 20, 2016 #2


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    Homework Helper
    Gold Member
    2017 Award

    Welcome to PF!

    You don't have the correct value of R if you are using SI units.

    They want you to use 4.8 K for T.

    Otherwise, your method looks correct.:smile:
  4. Jan 22, 2016 #3
    Thank You!!!!
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