How to Convert J/K and kgJs/m into m/s?

In summary, the conversation is discussing a conversion between J/K and m/s or kgJs/m and kg. However, it is concluded that these units are incommensurable and cannot be converted. Rajini then asks for help with a formula from a Solid State Chemistry journal, but upon further discussion, it is determined that the equation and units are correct. Finally, Rajini solves the problem and concludes that the conversion factor is 4.16×10-5/(dIS/dT) amu, with dIS/dT values in m/(sK).
  • #1
Rajini
621
4
Dear All,

J/K into m/s ?
Or
kgJs/m into kg?

thanks for your help!
Rajini.
 
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  • #2
There is no conversion because these are completely different units.

J is kg m^2/s^2, so things do not match.

J/K is the typical unit for heat capacity or entropy, while m/s gives a velocity.

Is there something wrong with the calculations or are non-SI units used? In natural units both the Boltzmann constant and c are equal to a dimensionless 1, while they have units of J/K and m/s in SI-units, respectively.
 
  • #3
These two units are incommensurable. They cannot be converted.
 
  • #4
seems one can do

Hello,
Sorry I did not give more information!
Please see this equation (taken from J. Solid state Commun, Vol. 33, p.361, 1980):
dIS/dT=-3EγkB/(2Mc2).
Here dIS/dT is in mm/(sK). This value can be obtained from plot.
Eγ=14412.497 eV.
M=56.9353987/(1000×6.02214179×1023) kg.
kB=8.6173324 eV/k=1.3806488×10-23 J/K.
c=299792458 m/s.
I measure IS vaules (in mm/s) for various temperatures (in K) and using the above formula I can plot IS values on y-axis and T on x-axis. Now find slope, i.e. dIS/dT (unit will be mm/(sK)).
Now can determine the M vaues in kg or amu.
But on considering the unit I am getting confused!
After rearranging the formula to
M=-3EγkB/(2c2(dIS/dT)).
After substituing the units I get
eV eV s2 s K/(K m2 mm)=eV2s3/(m2mm)=eV2s3 1000/m3.
Now I get M=2.0728216×10-14eV2s3/m3.
How to balance the units, how to convert the units in right hand side to get unit in kg??
Please help.

Thanks and regards, Rajini.
NOTE:
Useful conversion: 1 mm/s=48.075×10-9 eV.
 
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  • #5
Rajini said:
Please see this equation (taken from J. Solid state Commun, Vol. 33, p.361, 1980):

This reference does not exist. There is no J. Solid state Commun., so I suppose you mean Solid State communications which had a volume 33 in 1980, but there is no article starting on p. 361. The article ending on p. 361, "PHASE TRANSITION IN THE TRANSVERSE FIELD DEPENDENT ON THE DEFORMATION" does not contain your equation. Could you please provide the name of the article, so we can find it.

Rajini said:
NOTE:
Useful conversion: 1 mm/s=48.075×10-9 eV.

This also does not work as the units do not add up, so I assume that there is something set to 1 which makes it work. IF your above conversion works, also your equation works out.
 
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  • #6
Sorry I wrongly informed!
The correct one..see eq. 2 and table II..where the author computed M
Journal of Solid State Chemistry
Volume 33, Issue 3, 15 July 1980, Pages 361–369.
I already verified eq. 1 and 3..and they are correct in balancing the units..
PS:Finally I got 8.9686×10-6/(dIS/dT)s/m.
After this I don't how to proceed!
 
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  • #7
Oh, this is Mößbauer stuff.

If I remember correctly (I had to do some standard experiment while I was a student, so my memory might fail me here - please double check what I say here) they perform energy variations by applying Doppler shifts:
[tex]E_\gamma (v)=E_0 (1+\frac{v}{c})[/tex]
and it is quite common for some groups to only give the velocity when they actually mean the energy. So you might want to check, whether the values work out when you convert the velocities you get to energies that way.
 
  • #8
Cthugha said:
Oh, this is Mößbauer stuff.
Yes, one and only noble prize winner till now I saw in Munchen in 2009.[tex]E_\gamma (v)=E_0 (1+\frac{v}{c})[/tex] Yes I used this formula for mm/s to eV conversion.
E.g., Doppler shifted energy ED=vEγ/c. Here by taking v=1mm/s one can get 4.8075×10-8, i.e. 1mm/s=4.8075×10-8eV. Thinking of directly asking the author o:).

Thanks, Rajini.
 
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  • #9
Hello all,
I solved!
From my previous post we have
M=-3EγkB/2c2[dIS/dT].
Now taking Eγ in eV
kB in eV/K
c in m/s
dIS/dT in mm/(sK)
M=eV eV s2 s K/(K m2 mm)
= eV eV s2 s K/(K m2 10-3m)
Include 'kg' in numerator and denominator so J=kg m2/s2, which will cancel with one eV
M=eV s kg/m
substitute m/s in eV
Finally
M=4.16×10-5/(dIS/dT) amu. (dIS/dT values in m/(sK)).
I also checked with that paper and got the correct exact values reported there.
regards, raja.
 

Related to How to Convert J/K and kgJs/m into m/s?

1. How do you convert J/K into m/s?

To convert J/K (joules per kelvin) into m/s (meters per second), you need to use the formula: m/s = J/K * (kg*m^2)/(s^2*K). This formula represents the relationship between temperature, energy, and velocity.

2. Why is converting J/K into m/s important in scientific research?

Unit conversion is important in scientific research because it allows for consistency and accuracy in measurements. Converting J/K into m/s is particularly important in fields such as thermodynamics and fluid mechanics, where understanding the relationship between energy, temperature, and velocity is crucial.

3. Can you provide an example of converting J/K into m/s?

Sure, let's say we have a sample of gas with a temperature of 300 K and an energy of 100 J. To convert J/K into m/s, we use the formula: m/s = 100 J / (300 K * (1 kg*m^2)/(1 s^2*K)). This gives us a velocity of approximately 0.33 m/s.

4. What are some common units used for J/K and m/s?

J/K is commonly used to measure specific heat capacity (energy per unit mass per unit temperature change) and m/s is commonly used to measure velocity. Other related units include J/mol.K (energy per mole per unit temperature change) and m/s^2 (acceleration).

5. Is there an online calculator or tool for converting J/K into m/s?

Yes, there are many online unit conversion calculators and tools that can help you convert J/K into m/s (and vice versa). Some popular ones include UnitConverters.net, ConvertUnits.com, and OnlineUnitConversion.com. These tools are especially useful for quickly converting between different units without having to manually perform calculations.

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