Reduced mass to atomic mass units conversion help please

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Discussion Overview

The discussion revolves around the conversion of reduced mass into atomic mass units, specifically focusing on the calculation involving two similar masses and the resulting values presented in a textbook. Participants express confusion regarding the conversion process and the specific values used.

Discussion Character

  • Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant presents the equation for reduced mass as $$m_1m_2/(m_1+m_2)$$ and attempts to apply it to two similar masses, leading to a derived expression of $$1/2 * m$$.
  • Another participant questions the values presented in the book, noting a discrepancy between their calculation of $$m_4 = u$$ and the book's assertion of $$m_4 = 4u$$.
  • A third participant clarifies that $$m_4$$ refers to the mass of helium-4 ($$_2^4 He$$), acknowledging the oversight in their earlier calculation.
  • There is a suggestion on how to properly format inline LaTeX for clarity in future posts.

Areas of Agreement / Disagreement

Participants express confusion and uncertainty regarding the conversion values and the representation of mass in atomic mass units. There is no consensus on the correct approach or values, as discrepancies remain unresolved.

Contextual Notes

Participants have not fully clarified the assumptions behind their calculations or the definitions of the variables used, leading to potential misunderstandings in the conversion process.

TheCelt
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Hello

I am trying to understand how to write the reduced mass into atomic mass units but i am confused how it was done.

The equation is

$$m_1m_2/(m_1+m_2)$$

For two similar masses in my particular case i have:

$$m^2 / 2m = 1/2 * m$$

Then to convert to atomic mass units, the book says it gives:
1604877616274.png


But how did they get that value? I had $$1/2 * u$$My conversion must be failing me, i am not sure how they got that value..
 
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So the book has ##m_4 = 4u## while you have ##m_4 = u## ?

Hard to tell which is which on PF since ##m_4## hasn't been introduced here. Is it described somehow in the book ?
 
@BvU it was representing a $$_2^4 He$$

Don't know how to write it inline with my sentence, anyway it does seem I forgot that it would be 4u.
 
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All clear ! (the subscript 4 was a giveaway :wink: )

Inline ##\LaTeX## by enclosing it in double #: ##\LaTeX##
 

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