# Thread: Rearranging Flow Length Equation for Lava Flows! Confusion!

1. ## 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!

2. ## Re: Rearranging Flow Length Equation for Lava Flows! Confusion!

Can you write the information in a more comprehensible, less lazy way?

3. ## Re: Rearranging Flow Length Equation for Lava Flows! Confusion!

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.

4. ## Re: Rearranging Flow Length Equation for Lava Flows! Confusion!

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!
Originally Posted by marysmith

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:

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

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

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

5. ## 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!

6. ## 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.