Electromarnetisem/ Magnetohydronamics

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Homework Statement



Consider plane-parrallel, non magnetic single fluid flow in the z direction. Assume that the realtionship between pressure, velocity and density is constrained by equation (3), shown below.

Show that

\frac{P_{1}}{\rho_{1}} = \frac{5P_{0}}{3\rho_{0}}

Where

P_{0} and \rho_{0}

are the pressure and density of the uniform background on which a wave with small pressure and density fluctiations of

P_{1} and \rho_{1} propagates in the z direction.

Homework Equations




(1) \frac{d\rho}{dt} + \frac{d}{dz} (\rho v) = 0

(Mass Conversation)

(2) v = vz^

(3) \frac{d}{dt} [ \frac{1}{2} \rhov^{2} + \frac{3}{2}P ] + \frac{d}{dz} [v(\frac{1}{2} \rho v^{2} + \frac{5}{2} P )] = 0

(The Constraining equation)
Please note where the notation \frac{d}{dt/dz} has been used to indicate the partial differential (I'm not the best at Latex!)


The Attempt at a Solution



I'm not looking for an answer to this problem. This a set problem that I have been set, and am at a loss at how to tackle it. I can the see there is a realtionship between the conservation of mass equation and the constraining equation, however I can't see how to tackle it to show what is required.

Any thoughts of hints inthe right direction would be greatly appreciated.

Many Thanks

Leo
 
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