Cannot figure out how these conversion factors came about to this answer?

In summary, the conversation is about a person trying to figure out the conversion factors needed to solve an equation with known variables. The equation given is N/V = [2*pi*(2.315)/h^3][2*m*kT]^3/2 and the known variables are h = 6.6261E-34 j*s or 4.1357E-15 ev*s, m = 6.64E-26 kg, and kT = 2.5249E-2 eV. The answer to the equation is N/V = 2.5E28m^-3. The person asks for help and is reminded to show their work and use the LaTeX feature when posting.
  • #1
j2dabizo
19
0

Homework Statement



I have an equation with all known variables and I have the answer...I just can't figure out how they converted the variables and came about the answer.

The first equation is N/V = [2*pi*(2.315)/h^3][2*m*kT]^3/2

we have the known variables h (plank's constant)= 6.6261E-34 j*s or 4.1357E-15 ev*s
m= 6.64E-26 kg
kT= 2.5249E-2 eV

we know 1ev= 1.6022E-19 J and 1 J= kg*m^2/s^2

The answer to this equation is N/V= 2.5E28m^-3

I tried it many times and can't figure out the conversion factors to make this work!

thanks in advance


Homework Equations





The Attempt at a Solution

 
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  • #2
j2dabizo said:

Homework Statement



I have an equation with all known variables and I have the answer...I just can't figure out how they converted the variables and came about the answer.

The first equation is N/V = [2*pi*(2.315)/h^3][2*m*kT]^3/2

we have the known variables h (plank's constant)= 6.6261E-34 j*s or 4.1357E-15 ev*s
m= 6.64E-26 kg
kT= 2.5249E-2 eV

we know 1ev= 1.6022E-19 J and 1 J= kg*m^2/s^2

The answer to this equation is N/V= 2.5E28m^-3

I tried it many times and can't figure out the conversion factors to make this work!

thanks in advance


Homework Equations





The Attempt at a Solution


Could you please post your work, showing how you canceled the units and multiplied by any conversion factors? It would also help if you could use the LaTeX feature of posting. There is a LaTeX button in the Advanced Reply dialog, and a LaTeX tutorial in the Feedback forum as a stickie post.

Remember that you multiply and cancel units just like you do the variables in equations, and you can always multply by 1 = 1/1, where the 1/1 is some fraction that converts between units, like 1 = 100cm/1m.
 

1. How do you determine the conversion factors for a specific calculation?

The conversion factors for a specific calculation are determined by using the units of measurement involved and their relationships to each other. This can be done by using conversion tables or dimensional analysis.

2. What is dimensional analysis and how does it help with conversion factors?

Dimensional analysis is a method used to convert between different units of measurement. It involves identifying the starting and desired units, and then using conversion factors to cancel out units until the desired unit is achieved. This can help with determining the conversion factors needed for a specific calculation.

3. Why are conversion factors important in scientific calculations?

Conversion factors are important in scientific calculations because they allow us to convert between different units of measurement. This is necessary when working with data or measurements that have been collected using different systems or units.

4. Can conversion factors ever change or be inaccurate?

Conversion factors are based on established relationships between different units of measurement and are generally accurate. However, they can change if there are updates or changes to the units of measurement or if new information is discovered. It is important to use the most up-to-date conversion factors for accurate calculations.

5. How can I double-check my conversion factor calculations?

You can double-check your conversion factor calculations by using multiple sources and methods to verify the accuracy of your results. This can include using conversion tables, dimensional analysis, and checking for consistency with previous calculations. It is also helpful to have another person review your calculations for any potential errors.

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