Answer:
y = 0.44 m
Explanation:
As we know that path difference on the screen is given as
[tex]\Delta x = \frac{yd}{L}[/tex]
now for constructive interference we know that
path difference = integral multiple of wavelength
so we have
[tex]N\lambda = \frac{yd}{L}[/tex]
now for 4th maximum on the screen we can say
[tex]y = \frac{N\lambda L}{d}[/tex]
here N = 4
L = 170 cm = 1.70 m
[tex]\lambda = 363 nm[/tex]
also we know
path difference on screen = d[tex]sin\theta[/tex]
[tex]4\lambda = dsin14.9[/tex]
[tex]d = \frac{4\lambda}{sin14.9}[/tex]
now we have
[tex]y = \frac{4(\lambda)(1.70)}{\frac{4\lambda}{sin14.9}}[/tex]
[tex]y = 0.44 m[/tex]