Question

A speaker, speaker A, is 2.00 m in front of you playing a single frequency 35.00 Hz.* A second speaker, speaker B, is placed behind speaker A, further from you and along the line from you to speaker A. The speaker B plays the same frequency and the difference in phase constant between the two speakers is oo = 1/2 a) At what distance from you, further than the first speaker, do you need to place the second speaker so that there is total deconstructive interference, amplitude zero at all times, at your location? Assume 20 °C. = There are a discrete set of infinite answers and I will accept any of them.

Answer 1

x am < f = 35 H3 40% = 1/2 T= 20°C Velocity of sound at 20°, U= 343 m/s ? Wavelength, f = 343 f 35 x=9.8m le Total - Path difference, 18% = By - AY the waves between coming from Band A 4 с х total phase difference, 2T Txa 2 2 TN d The initial phasee difference = 72 to have a destructive interference the waves coming from A and B must have t phase difference : the phase difference reauired due to the additionat path difference - H-1/2 = 1/2 : Hence, 8W¥ -*) 2 = 2.2 = 2.45m : The speaker must be placed (2+2.45) = 4.45€ from you and 2.45m from A.