00:01
So for this question, which is problem 70 from chapter 25 of the physics fifth, we have a double step problem and we need to find for part of the separation between the m1 interference of the two colors, green and violet, and then for part b, the separation of the m2 maximum beam.
00:21
So standard stuff, tan theta is equal to x over d, where x is the distance on the screen it travels.
00:30
The distance on the screen the certain order of the maxima reaches d is the distance from the screen to the splits and theta is this angle here.
00:41
So we get tan theta is equal to x over d so x is equal to d tanned theta.
00:49
So d sine theta and now we use d sine theta is equal to m lambda so therefore for m is equal to one theta is equal to the inverse side of lambda over 0 .0 .020 times centre minus 3, which is our slit separation.
01:07
And so our theta green is 1 .5 degrees.
01:11
And so our x green is tan of 1 .5 times 0 .72, which is just the distance green.
01:18
So we come up with 1 .87 centimeters...