Question

Two sound waves, originating from the same source, travel aong difeent paths in air and then meet at a point. If the source vibrates at a frequency of 1.0 kHz and one path is 83 cm longer than the other, what iwill be theture of iterference? The speed of soundin air is `ms^-1`.

Answer 1

The wavelength of sound wave is `lamda=u/v`
`=(332ms^-1)/(1.0xx10^3Hz)=0.332m`.
The phase difference the waves arriving at the point of observation is
`delta=(2pi)/lamda /_x=2pixx(0.83m)/(0.332m)=2pixx2.5=5pi`.
As this is an odd multiple of pi the waves interfers destructively.