For a home sound system, two small speakers are located 52 cm closer to the listener than the other. for what value of the fundamental frequency of audible sound will these speakers produce constructive interference at the listener? speed of sound is 344 m/s

661.54 Hz

Explanation:

The lowest frequency (n=1) for the constructive interference is known as the fundamental frequency. For constructive interference, the difference in the distances of the speakers from the observer is equivalent to the multiple of the wavelength. Thus:

For fundamental frequency, the wavelength = 0.52/1  = 0.52 m

We know that: V = f*λ

V = speed of sound = 344 m/s

f = fundamental frequency = ?

λ = wavelength = 0.52 m

f = V/λ = 344/0.52 = 661.54 Hz

if the thermos has a vacuum innner, then heat through conv currents and conduction are reduced = vacuum flask