Problem with units? (trying to solve a normalized function)

  • Thread starter Thread starter Labboi
  • Start date Start date
  • Tags Tags
    Function Units
Click For Summary

Homework Help Overview

The discussion revolves around a problem related to the calculation of a normalized function in the context of a deuteron, specifically involving the reduced mass, binding energy, and the conversion of units. Participants are attempting to clarify their calculations and unit conversions.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • Participants are exploring the correct application of units in their calculations, questioning the arithmetic involved, and discussing the conversion of femtometers to centimeters. There are attempts to clarify the relationship between energy and mass in the context of relativistic equations.

Discussion Status

The discussion is active, with participants providing feedback on arithmetic errors and unit conversions. Some guidance has been offered regarding the correct use of constants and the need for careful arithmetic, but there is no explicit consensus on the calculations being correct.

Contextual Notes

There are indications of confusion regarding the definitions of units, particularly femtometers and their conversion to other units. Participants are also addressing potential discrepancies in the values used for the mass of the deuteron.

Labboi
Messages
5
Reaction score
0
Homework Statement
I'm trying to solve a normalized function and cannot seem to get the right answer.
Relevant Equations
Kappa=sqrt(2m(EB)/hbar^2))
-kappa*R=-0.34
I'm trying to solve for this in a deuteron problem. But can't seem to get the right answer.
The reduced mass of the deuteron is 469.4 MeV, the binding energy Eb is 2.226 MeV and R = 1.5fm.

Using hbar = 6.5817x10^-16 eV.s

I get Kappa = sqrt((2(469.4)*2.226)/(6.5817*10^-22)^2) = 6.94*10^16

-kappa*(1.5*10^-13) = 10418.

I feel like I'm messing up units or something.
 
Physics news on Phys.org
fm=1.0 E-15 m, but your arithmetic has other errors as well. Google of the mass of the deuteron also is in disagreement.
 
Labboi said:
I feel like I'm messing up units or something.
Like not including them on your answer? Have you tried including the units and working out the end result?
 
Charles Link said:
fm=1.0 E-15 m
I disagree. One fm is ##10^{-6}~\rm nm##.
 
When you put in for the mass, ## m=E(in \, MeV)/c^2 ##.
 
vela said:
I disagree. One fm is ##10^{-6}~\rm nm##.
Then, in fact, you agree with @Charles Link!
 
  • Like
  • Haha
Likes   Reactions: berkeman, vela and Charles Link
Kappa = Sqrt((2(469.4MeV/3.0*10^8m.s^-2)*2.226Mev)/(6.5817*10^-22MeV.s)^2 = 5939.86

-Kappa*R = 5939.86*1.5*10^-13 = 8.90*10^-13

I'm trying to convert the fm into cm
 
You need to take ##c ## to the second power. In addition ## \hbar ## is to the second power inside the square root. You need to do the arithmetic carefully.
 
  • Like
Likes   Reactions: Labboi
I did, just forgot it in the equation, sorry.
 
  • #10
Thank you, I must have messed up my parentheses, it's been a long night.
 

Similar threads

Replies
12
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
14
Views
2K
  • · Replies 14 ·
Replies
14
Views
3K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K