IIT JEE , AIEEE Forum - Physics , Mechanics

joyfrancis

Q) Two waves of equal amplitude A and equal frequency travel in the same direction in a medium. the amplitude of the resultant wave is

1) 0

2) A

3) 2A

4) between 0 and 2A

Q) Two waves represented by y=asin(

t-Kx) and y=acos(

t-Kx) are superimposed ; the resultant wave will have amplitude

a) a

b) a

2

c) 2a

d) 0

Q) The wave equation y=Asin²(kx-

t) represents a wave motion with

Amplitude=.......

frequency=.......

punitcooldude

the answer to the first one is 4) bcoz these waves can undergo constructive or destructive interference depending on their phase diff,.

2) y=acos(

t - kx)

y = asin(

t - kx +

/2)
As the phase difference b/w the 2 waves is

/2, treat thier amplitudes at a pt. as vectors with

/2 angle b/w them. By principle of superposition, we add these vectors to get the resultant amplitude which comes out to be a

2.

3)u can do this graphically, plot the graph of this function to get a wave
u would see its amplitude is A and frequency is 2n where
n=

/2

rate the answer if u like it

abhijeet_0201

punit your ans for 3rd ques is wrong

its A/2.
bec sin^2(kx-wt)=(1-cos2(kx-wt))/2
so the eq becomes y=(A/2)(1-cos2(kx-wt))
so amp=A/2

also
T=2pie/w n=w/(2pie)
here w=2w (y=(A/2)(1-cos(2kx-2wt))
n=w/pie
plz rate me if u like!!!

punitcooldude

thnx for correcting me abhijeet.

abhijeet_0201

u r welcome!!!!!!!

punitcooldude

abhijeet could u answer my ques. on pan balance in mechanics section?

Ask & Discuss Questions with Community & Experts