Two cellists, one seated directly behind the other in an orchestra, play the same 220-hz note for the conductor who is directly in front of them. what is the smallest non-zero separation that produces constructive interference? take the speed of sound to be 343 m/s.

Constructive interference defination:

''Constructive interference occurs when the maxima of two waves add together (the two waves are in phase), so that the amplitude of the resulting wave is equal to the sum of the individual amplitudes''

Constructive interference occurs at integer multiples of the wavelength of the wave. The lowest incidence occurs at the wavelength.

As we know,

                      wavelength * frequency = velocity

                      wavelength = v/f

                                          = (343 m/s) / (220 1/s)

                                          = 1.56 m

the reason is because the moon has some form of gravity, and that gravity pulls the ocean tides.