Question

The figure shows the light intensity on a screen behind a double slit. The slit spacing is 0.20 mm and the wavelength of the light is 600 nm. What is the distance from the slits to the screen (in cm)? 

Answer 1

$$ \begin{array}{l} \lambda=x \mathrm{~d} / \mathrm{nL} \\ \mathrm{x}=1 \mathrm{~cm} \\ \mathrm{~d}=0.2 \mathrm{~mm} \\ \mathrm{n}=2 \\ \lambda=600 \mathrm{nm} \\ 600 * 10^{-9}=1 * 10^{-2} * 0.2 * 10^{-3} /(2 * \mathrm{~L}) \\ \mathrm{L}=166.67 \mathrm{~cm} \end{array} $$