Unformatted text preview: 1.4 in Kinsler et al. 7. Problem 5.11.2 in Kinsler et al. for 10 Hz, 100 Hz and 1 kHz. Use air at 20C. 8. At what distance from a point source can a spherical wave be considered as a locally plane wave if the admissible error in determining the particle velocity from a pressure amplitude measurement is not allowed to exceed 10%? Express the distance in terms of the acoustic wavelength. 9. Find the specific acoustic impedance for a standing wave with acoustic pressure given by p ( x, t ) = p oSin ( kx ) e j!t . EXTRA: Try these problems. They will not be graded but the answers will be provided.
2 E1. In class we developed an expression for c based on Equation 5.2.4 in Kinsler et al. where 2 c was a function of the excess density ! e . Derive an expression for c 2 as a function of ! e when one additional term of Equation 5.2.4 is considered, that is, the (! " ! o ) term.
3 E2. A 10-kHz plane acoustic wave with a 0.5-MPa acoustic pressure amplitude at the source is propagated in water at 20C (B/A = 5). A student is using an acoustic detector capable of measuring both the 10-kHz fundamental freq...
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- Fall '08
- Wavelength, Sound pressure, Kinsler, peak condensation amplitude, acoustic pressure amplitude, excess density amplitude