- #1
mk55
- 1
- 0
Homework Statement
Consider a pulsating sphere of radius 0.15m pulsating at a frequency of 2000Hz and surface velocity v[itex]_{}0[/itex]=0.07m/s. What is the distance r, where the measured acoustic pressure is 5x10[itex]^{}-2[/itex].
speed of sound c=343m/s
mass density of air ρ[itex]_{}0[/itex]=1.25kg/m3
Homework Equations
i know I am supposed to use these equations:
φ=(A/r)e^(ikr-iωt)
p'=-ρ[itex]_{}0[/itex](dφ/dt)
v=dφ/dr
v=v[itex]_{}0[/itex]e^(-iωt)
The Attempt at a Solution
I have differantiated the velocity potential function (φ) and substituted in the formula for p'. i also substituted the value of p' which is 5x10^-2 but after that I am stuck because I am not sure how to work out t.
Any help would be appreciated