Question

Hi, is it possible to solve this equation:

u (∂lnγ/∂x) = (-1/p) (∂p/∂x)

Answer 1

Ghostdog, did you know you can chat with users in the mathematics group, thus get help from experts?

Answer 2

Nope, first time. Where do I go?

Answer 3

Just the green box below

Answer 4

Thanks

Answer 5

I am actually chatting with you right now

Answer 6

Okay, what are we supposed to do?

Answer 7

hmm partial derivatives..

Answer 8

nenand, save the day? plz?

Answer 9

well, what is p? is it a function, constant?

Answer 10

it's a variable.. i think

Answer 11

What I'm trying to do is to calculate u. p is a variable.

Answer 12

just divide both sides by d(lny)/dx then

Answer 13

This is the formula for calculating horizontal wind speed (u). p is atmospheric pressure and y is the mixing ratio.

Answer 14

ok...If u is the function which argument is partial derivative of lny, then that derivative of lny is 0 so you have u(0)

Answer 15

if y is not y(x) of course

Answer 16

I am not too sure. I got it from this article: http://www.bioticregulation.ru/common/pdf/ijw10.pdf; see equation 17

Answer 17

I have p for two points on the x axis. y is the mixing ratio depending on x, it is not the y-axis

Answer 18

So, imagine we a point x1 and x2, that have p1 and p2 of 1050mbar and 1000mbar, respectively. y1 and y2 are about 0.05 and 0.04 respectively. What I want to calculate is u

Answer 19

ie the wind speed between these two points

Answer 20

hmmm...there's a lot of material above this equation....a lot of physics....not so sure about this....maybe if u(0)=0, in that case you will get basic equation where the only solution is that that partial derivative of p is 0....but, just assuming, because I don't have basics of physics to this with understanding...sorry :(

Answer 21

I think that the best way is to post this in some physics group...

Answer 22

I will do this. thanks for your time anyways

Answer 23

if u is 0 then the pressure p at point x1 and x2 are the same

Answer 24

not sure but:

u (∂lnγ/∂x) = (-1/p) (∂p/∂x)
^^^
this = 0 since lny is a constant with respect to x

or is the notation misleading?

Answer 25

yeah, theres alot of stuff going on way before this to sort out ...

Answer 26

Thanks a lot amistre!