First Order Nonlinear Partial Differential Equation

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Homework Help Overview

The discussion revolves around a first order nonlinear partial differential equation (PDE) with specified initial and boundary conditions. The equation presented is dv/dt + A*(v^2)*dv/dx = 0, where A is a constant. Participants are exploring methods to approach the problem.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • The original poster considers using the method of characteristics but expresses uncertainty about its applicability. Another participant suggests a transformation of the equation and proposes a potential approach involving fitting to initial conditions.

Discussion Status

The discussion is in an exploratory phase, with participants sharing initial thoughts and approaches. Some guidance has been offered regarding potential methods, but there is no explicit consensus on the best way to proceed.

Contextual Notes

There is a mention of uncertainty regarding the classification of the equation as nonlinear, indicating a potential area of confusion or differing interpretations among participants.

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I have derived a first order nonlinear PDE with its corresponding initial and boundary conditions given by:

dv/dt + A*(v^2)*dv/dx = 0 (where A is a constant)

v(t = 0) = C (constant value)
v(x = 0) = 0

I'm not quite sure how to solve this. I was thinking about using the method of characteristics, but since I haven't had too much experience with it, I'm not sure if it would be applicable here. If anyone has any hint on how to get started, I would really appreciate it. Thanks in advance.
 
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I have no experience either but to get started what I would do is write that

\frac{∂v}{∂t}/\frac{∂v}{∂x} = -Av^2

Then at constant v

( \frac{dx}{dy})_v = Av^2

x = Av^2t + K at constant v.

Fitting that to your initial conditions generates your surface I think. :rolleyes: Something like that.
 
Solved! Thanks!
 
They don't count that as non-linear AFAIK though.
 

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