Answer:
Explanation:
Minimum intensity occurs due to destructive interference of sound. For it to take place ,
path difference = odd multiple of half wave length
When moved by .025 m ,
path difference created = ( x + .25 ) - ( x - .25 )
= 2 x .25
= .5 m
So .5 = half wave length
wave length = 2 x .5
= 1 m
frequency = velocity / wave length
= 343 / 1
= 343 Hz
B )
Now when frequency is increased , wave length will be decreased . For maximum intensity , constructive interference will have to take place .
For that
path difference = integral multiple of wave length
0.5 = 1 x wave length
wave length = .5
frequency = 343 / .5
= 686 Hz