How Do I Find the Distance Between Two Waves in Superposition?

[bilals]

Homework Statement

2. The attempt at a solution

i knew how to solve questions one and three..please help me in question number 2...here is what i did...


Question 1

(2*pi*x)/(wavelength)=pi/3

where x is the distance between the two waves (5cm)

and therefore we get the wavelength = 30cm



Question 2

(2*pi*x)/30 - wt = difference in phase

(2*pi*x)/30 - (2*pi*f)(7.5*10^-3) = difference in phase

is this correct,,if so how can i get x ..because i think it would be different


Question 3

v = wavelength * frequency
= 0.3*45

 

[bilals]

can anybody help...please

 

[bilals]

i tried myself and i got the correct answer for question number 2

difference in phase = wt
difference in phase = (2*pi*f)(7.5*10^-3)
difference in phase = (2*pi*45)(7.5*10^-3)

then divide by pi ..to get the answer as a multiple of pi