Calculating Helium Vrms and Average KE at 5K

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The discussion revolves around calculating the root mean square speed (Vrms) and average kinetic energy (KE) of helium at 5K. The initial calculations yielded incorrect results, prompting questions about unit conversions and the values used for the Boltzmann constant (kB), temperature (T), and mass (m). A key issue identified was the need to convert atomic mass units (amu) to kilograms for accurate results. After addressing the conversion, the user was able to find the correct answers. The conversation highlights the importance of unit consistency in physics calculations.
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Homework Statement



What is the root mean square speed of Helium at 5K?

Homework Equations



Vrms=sqrt((3kbT)/m)

The Attempt at a Solution



I plugged all the numbers in and keep getting 7.19*10-12. The computer keeps telling me that it is not correct. The next question ask for the avg KE which I found to be 1.04×10−22. I tried using 2/3 Kavg/kb and got 7.21*10-12. The computer tells me that is wrong also. Where am I messing up?
 
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Did you check the units on kB, T, and m? What values did you use for them?
 
That is the whole proble. I remember overhearing the professor and another student talking about converting amu to kg. I plugged in the conversion and got the answer. It has been a long week and day. Guess my brain is still fried from the calculus test tonight. Thanks for the help.
 

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I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
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Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
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