Question #c53c7

1 Answer
Feb 7, 2017

Given the common oscillator frequency is

ν=7.80×102Hz=780Hz

Velocity of sound V=343ms1

So the wave lenhth of sound created from each spreaker will be λ=Vν=3437800.44m

Here a stationary wave will be formed due to superposition of two similar waves approaching from opposite sides.The distance between its two consecutive nodes will be λ2=0.442m=0.22m.

If the two speakers vibrate in phase, the point halfway between them will be an antinode of pressure and the distance of this antinode point (minimum) from either of the speaker will be =1.273m=0.635m Let this position be named as M.

The distances of other nodes from the left side (at the left of mid position)

L1=0.635λ4=0.6350.11=0.525m

L2=0.525λ2=0.5250.22=0.305m

L3=0.305λ2=0.3050.22=0.085m

The distances of other nodes from the left side (at the right of mid position)

R1=0.635+λ4=0.635+0.11=0.745m

R2=0.745+λ2=0.745+0.22=0.965m

R3=0.965+λ2=0.965+0.22=1.185m

Hence the positions of the relative minima on the line joining the positions of two speakers will be as follows (from left)

L3=0.085m,L2=0.305m,L2=0.525m,M=0.635m,R1=0.745m,R2=0.965m,R3=1.185m