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Kinetic Energy of gas Molecules 
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#1
Dec708, 10:39 AM

P: 3

Hi, the question, I'm having problems with is this:
A 1.0 mol sample of hydrogen gas has a temperature of 30 C. What is the total kinetic energy of all the gas molecules in the sample? How fast would a 75 kg person have to run to have the same kinetic energy? Relevant equations: K = (3/2)kT or K = (3/2)nRT Ok, so I tried using both formulas: (3/2)(1.38*10^23)(30+273) = 6.2721 * 10^21 Then, since its one mole and the question asks for the total KE, I multiplied this answer by Avogadro's number (6.02*10^23) and got = 3775.8042 Joules. For the second part, I would just set this number equal to 0.5mv^2 and solve for v but since I got the first one wrong, it doesn't quite work :( I really need help; I thought I had the right idea but it's not working out. Thanks 


#2
Dec708, 11:23 AM

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[tex]v = \sqrt{2E/m}[/tex] AM 


#3
Dec708, 11:35 AM

P: 3

I thought my method was right but my homework webassign isn't accepting that answer :( It asked for it in 2 sig figs so i put it in as 3.8 *10^3 but it still said no... 


#4
Dec708, 07:38 PM

P: 3

Kinetic Energy of gas Molecules



#5
Dec808, 09:01 AM

Sci Advisor
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P: 6,653

AM 


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