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Need to know what the K stands for in this equation

  1. May 16, 2012 #1
    I'm busy solving a physics question and I am getting unexpected results.

    I just want to check if I am using the right constant in this equation:
    I am using the equation to find the Root Mean Squared speed = √(8/3∏) √3kT/m

    Is k in this equation the boltzman constant? (1.4e-23)
     
  2. jcsd
  3. May 16, 2012 #2

    Matterwave

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    Yes it is. (As long as you are indeed talking about the RMS speed of a molecular gas or some such at temperature T with molecular mass m)
     
  4. May 16, 2012 #3
    Thanks. Then I must be going wrong somewhere else.. I'm sure I'll find it. Thanks again
     
  5. May 17, 2012 #4

    arildno

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    T is in Kelvin, is that the temperature scale you have used?
     
  6. May 17, 2012 #5

    QuantumPion

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    Make sure your temperature is in absolute scale (e.g. Kelvin), not degrees.
     
  7. May 17, 2012 #6
    I've used kelvin. And mass in kilograms.

    Thanks for the input. I'll post the actual question later and you could see if I've done it correctly or not.
     
  8. May 17, 2012 #7

    arildno

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    Have you been careful and told your calculator what the correct radicands are? That is, have you used parantheses around the full expression that should stand under the square root signs?
     
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