waves help

[AN10]

plz solve question no 5 of first variant paper attached below

[vanibharutham]

For a wave to a have a minima, there must be destructive interference i.e. a phase difference of Pi radians...

However to detect a minima of ZERO, you must have a) A phase difference of Pi Radians b) Same Amplitude

[AN10]

k i get it.... can u plz solve da second part too

[AN10]

anyone

[astarmathsandphysics]

I will do it when I get home in 1 hour

[astarmathsandphysics]

Distance frim S_2 to M is sqrt(1^2 +0,8^)=1.28m
so path difference =0.28m
when f=1kHz wavelength=v/f=330/1000=0.33
When f=4kHz wavelength=330/4000=0.0825
minumum whenw/2=28 or 3w/2 =28 or 5w/2=28 or 7w/2 =28
w=56 or w=18.7 or w=11.2 or w=8
only two of these are between 8.25 and 33
so only two minima

[AN10]

ok....thanx a lot!!

[halosh92]

Distance frim S_2 to M is sqrt(1^2 +0,8^)=1.28m
so path difference =0.28m
when f=1kHz wavelength=v/f=330/1000=0.33
When f=4kHz wavelength=330/4000=0.0825
minumum whenw/2=28 or 3w/2 =28 or 5w/2=28 or 7w/2 =28
w=56 or w=18.7 or w=11.2 or w=8
only two of these are between 8.25 and 33
so only two minima

i dont get this part only:
minumum whenw/2=28 or 3w/2 =28 or 5w/2=28 or 7w/2 =28

[astarmathsandphysics]

w is the wavelenfth and mimima where paths difference  is w/2 or 3w/2 etc

[astarmathsandphysics]

cos that means destructive interference