In: Physics
Suppose that two speakers are connected to a single nail with two strings to form a triangular shape. One string has a 3rd harmonic wave of 300 Hz and weighs 3 g/m. The other string has a fundamental frequency of 400 Hz and weighs 4 g/m. Both strings have a tension of 2N
When the speakers play at 1600 Hz, what interference happens at the location of the nail?
Speed of sound is 343 m/s
Third harmonic of first string is
and fundamental frequency of second string
Third harmonic frequency of standing wave
and fundamental frequency of standing wave
Velocity of wave on first string
and velocity of wave on the second string
That is the distance between first speaker and nail is
and distance between the second speaker and the nail is
Difference between the distances
is the path length of two sound waves from two speakers.
Wavelength of sound wave is
For sonstructive interference at nail,
For destructive interferece at nail
where
From the values of
, and
So
Hence at the position of nail, destructive interference happens .