Name: _______________________

Quiz 2

02/07/2006

Ch. 16-17

The speed of sound in air is 344 m/s. The threshold of hearing I₀ is 10^-12 W/m².

1) A woman stands 1.2m from speaker A and 1.6m from speaker B, which are each playing a 20dB pure tone in-phase.

a) What is the longest wavelength sound that will constructively interfere at the woman's position?

b) What is the frequency of the tone?

c) Can an average human hear this pitch?

d) What is the combined sound level of the tone?

e) What is the sound intensity?

2) The high E string on a guitar should have a fundamental frequency of 659.2 Hz.

a) If the string is 0.8m long and the lineal density (m/l) is 1.7 x 10^‑3 kg/m. Find the tension of the string to bring the guitar in tune (i.e., make the fundamental frequency equal 659.2Hz).

b) Once the string is tuned what will be the frequency of the 3^rd overtone (or fourth harmonic)?