Two sound sources oscillate in phase with the same amplitude A. They are separated in space by 6 - What is the amplitude (as a multiple of A) of the resultant wave formed from the two sources at a point that is on the line that passes through the sources but is not between the sources?

ZOOM + 1) Suppose we have an air column 80cm long with one open end and one closed end. (a) Find (i.e. derive) an expression for the resonant frequencies of the air column in terms of the length L of the air column, the speed of sound v, and the harmonic number n. Don't simply write the equation – show me how you obtain it by sketching several resonant standing waves. (b) What are the three lowest resonant frequencies in this air column (numerical values)? Take the speed of sound in air to be 343 m/s.

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1. The low-frequency speaker of a stereo set has a surface area of 0.05 m and produces 1 W of acoustical power. (a) What is the intensity at the speaker? (b) If the speaker projects sound uniformly in all directions, at what distance from the speaker is the W intensity 0.26 -? m2 Hint: If the sound projects uniformly in all directions, after traveling a distance r it is uniformly distributed over a sphere of area r. What is the surface area of a sphere of radius r? W (a) Intensity: m? (b) Distance (radius), r: m