Three sources of sound and of equal intensity are placed in a straight line with (figure below). At a point , far away from the sources, the wave coming from is ahead in the phase of that from . Also, the wave coming from is ahead of that from . What would be the resultant intensity of sound at ?
Step 1: Given Data
Let the amplitude of the sound source from be .
Let the amplitude of the sound source from be .
Let the amplitude of the sound source from be .
is ahead of .
is ahead of .
They have equal intensities,
Step 2: Formula Used
Relationship between intensity and amplitude,
Step 3: Phasor Diagram
Step 4: Calculate the Resultant Intensity
Since they have equal intensities,
Therefore, the intensity at point ,
Therefore, by vector method the resultant intensity at point
Hence, the resultant intensity and point is zero.