Density equation of sound wave

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
2 replies · 3K views
abhineetK
Messages
18
Reaction score
0
Let pressure equation of sound wave be
[tex]\Delta[/tex]p=Pocos([tex]\omega[/tex]t-kx), then
what will be the density equation of the sound wave?
give your answer with proof and proper explanation...(Derive the equation)
 
Physics news on Phys.org
[tex]\delta[/tex]P=Pocos([tex]\omega[/tex]t-kx) ...(1)

B=-[tex]\delta[/tex]P/([tex]\Delta[/tex]V/V) ...(2)

[tex]\rho[/tex]=m/V

=>[tex]\partial\rho[/tex]=-(m/V2)[tex]\partial[/tex]V

=>[tex]\partial\rho[/tex]=-[tex]\rho[/tex]([tex]\partial[/tex]V/V)

=>[tex]\partial\rho[/tex]/[tex]\rho[/tex]=-[tex]\partial[/tex]V/V

=>[tex]\partial\rho[/tex]/[tex]\rho[/tex]=[tex]\delta[/tex]P/B [using (2)]

=>[tex]\partial\rho[/tex]=([tex]\rho[/tex].Po/B)cos([tex]\omega[/tex]t-kx) [using (1)]
Is it correct?