A slit of width 0.010 mm has light of frequency 5.0 x 10^14 Hz passing through it onto a screen 60 cm away. How wide is the central maximum? (c =...

Here, we have a problem where light passing through a slit forms a diffraction pattern. This pattern will have bands of light at intervals, going from light to dark and back again. The brightest band is called the central diffraction. To calculate the width of this bright band, we can use the equation `y=lambdaL/a` where y is the distance from the central diffraction maximum, or the brightest point in the band, to the central diffraction minimum,...

Here, we have a problem where light passing through a slit forms a diffraction pattern. This pattern will have bands of light at intervals, going from light to dark and back again. The brightest band is called the central diffraction. To calculate the width of this bright band, we can use the equation `y=lambdaL/a` where y is the distance from the central diffraction maximum, or the brightest point in the band, to the central diffraction minimum, the first point with no light. Because the length y is only half of the width of the central band, y must be multiplied by two. To calculate the wavelength, remember to divide c by the frequency.

When I ran the numbers, I calculated a width of .072 meters, or 7.2 centimeters. 

For more advice on this problem, this has a full derivation of the problem complete with pictures.