Light whose wavelength is 633nm falls on a double slit with spacing of 0.100mm. what is the separation between the 0th and 1st order peak on a screen, l=1.20m from the double slit?

Approximately 0.00760 m (that's 7.60 mm.)

Explanation:

Refer to the first diagram attached. For a double-slit diffraction, the angle (angular separation) between the m-th maximum and the central maximum satisfies the following equation:

, where

(Young’s Double Slit Experiment, OpenStaxCollege)

If is much larger than , the value of will be considerably small. The value of could thus be approximately as:

.

For this problem,

Approximate the value of :

.

Separation between the first and central maximum:

f=ma a/f/m a= 480/60 a = 8m/s/s that is quick wow

0.11 m/s and 0.28 m/s should be correct