Question

Estimate the distance (in cm) between the central bright region and the third dark fringe on a screen 5.00 m from two double slits 0.500 mm apart illuminated by 500-nm light.

Answer 1

y = 1.75 cm

Step-by-step explanation:

In the double-slit experiment the equation for destructive interference is

d sin tea = (m + ½)

λ

let's use trigonometry to find the angle

tan θ = y / L

as all the experiment does not occur at small angles

tan θ = sin θ / cos θ = sin θ = y / L

we substitute

y = (m + 1/2 ) λ L / d

we calculate

y = (3 + ½) 500 10⁻⁹ 5.00 / 0.5 10⁻³

y = 1.75 10⁻² m

y = 1.75 cm