# Rearranging Flow Length Equation for Lava Flows! Confusion!

• March 13th 2013, 07:47 AM
marysmith
Rearranging Flow Length Equation for Lava Flows! Confusion!
Rearrange for Q:

L
m = (3 x extension x S)
(D x G x K ) multiply everything in equation by Q1/2

Lm= Flow length
S = Tensile Strength
D = Density
G = Gravity
K = Thermal diffusivity
Q = Flow/effusion rate

I am having a bit of trouble with the way I've rearranged this, as it does not fit my model. Just want to see if anyone gets the same rearrangement as myself.

THANKS!
• March 13th 2013, 09:05 AM
Shakarri
Re: Rearranging Flow Length Equation for Lava Flows! Confusion!
Can you write the information in a more comprehensible, less lazy way?
• March 13th 2013, 09:39 AM
marysmith
Re: Rearranging Flow Length Equation for Lava Flows! Confusion!
Attachment 27515

I've attached the equation here.
I'm sorry, but I could not figure out how to write it correctly, especially on this. Everytime I uploaded it, it kept changing my spacing, etc.
• March 13th 2013, 01:37 PM
ILikeSerena
Re: Rearranging Flow Length Equation for Lava Flows! Confusion!
Quote:

Originally Posted by marysmith
Rearrange for Q:

L
m = (3 x extension x S)
(D x G x K ) multiply everything in equation by Q1/2

Lm= Flow length
S = Tensile Strength
D = Density
G = Gravity
K = Thermal diffusivity
Q = Flow/effusion rate

I am having a bit of trouble with the way I've rearranged this, as it does not fit my model. Just want to see if anyone gets the same rearrangement as myself.

THANKS!

Quote:

Originally Posted by marysmith
Attachment 27515

I've attached the equation here.
I'm sorry, but I could not figure out how to write it correctly, especially on this. Everytime I uploaded it, it kept changing my spacing, etc.

Hi marysmith! :)

You can write you equation like this:

[TEX]L_m = \left[ \frac {3 \varepsilon S} {\rho g \kappa} \right]^{1/2} Q^{1/2}[/TEX]

$L_m = \left[ \frac {3 \varepsilon S} {\rho g \kappa} \right]^{1/2} Q^{1/2}$

I'm not sure I understand your question correctly.
It seems you want to isolate Q.
If that is the case, you can do:

$L_m = \left[ \frac {3 \varepsilon S} {\rho g \kappa} \right]^{1/2} Q^{1/2}$

$Q^{1/2} = \left[ \frac {\rho g \kappa} {3 \varepsilon S} \right]^{1/2} L_m$

$Q = \left[ \frac {\rho g \kappa} {3 \varepsilon S} \right] L_m^2$
• March 13th 2013, 01:56 PM
marysmith
Re: Rearranging Flow Length Equation for Lava Flows! Confusion!
Thank you so much ILikeSerena! I definitely was rearranging this incorrectly, and now I see where I went wrong.
Also, thanks for explaining how to properly enter the equations, not use to this stuff!
I needed it to enter it into a spreadsheet, and work out some estimate values.

Thank you so much!
• March 13th 2013, 02:45 PM
ILikeSerena
Re: Rearranging Flow Length Equation for Lava Flows! Confusion!
All in good time I guess. ;)
I found it pretty useful to know this $\LaTeX$ stuff.