The figure below shows two identical audio speakers acting as coherent sources o
ID: 1916613 • Letter: T
Question
The figure below shows two identical audio speakers acting as coherent sources of spherical sound waves. The speakers are in phase with each other (Delta 0 = 0 rad), and the wavelength of the waves is 3/4 of a meter. The speakers arc a distance of 8 meters apart. The distance r1 is 10 meters. When the waves combine at the point A, which is equidistant from the two speakers, the intensity of the sound is IA. (NOTE: in this problem consider superposition effects only) When the waves combine at point B, What is their path difference? What is their phase difference? What is the resulting intensity relative to IA? That is, what is the ratio IB/IA? What is the frequency of the sound wave? (hint: you may need to use the information provided with the formula sheet). Is this sound audible to the human ear (most people can detect sound between 20 Hz and 20,000 Hz). If the sound intensity level at point A, due to both speakers, is 65 dB. what is the corresponding sound intensity level at point B? (note: if you were unable to get an answer to part (c), use IB/IA = 0.1).Explanation / Answer
1) r2-r1=10-6=4
2)angle = tan-1(8/6)
3) resulting intensity = (I^2+Ib^2+2*Ia*Ib*cos()