AL physics 2006

8. Wavelength, s = v/f = 8/2 = 4 m

The parallel lines represent the wave crests, so for every parallel lines, the separation, d

= 1 wavelength

= 4 m

And the resulting phase difference = 2π

Now, consider the two points that the two parallel lines apart along the wall, the separation, d'

= d/sin(π/6)

= 2d

= 8 m

So, by the equation,

D / d' = φ / 2π

1 / 8 = φ / 2π

The phase difference, φ = π/4