00:01
This problem is about diffraction.
00:04
We have two different kinds of diffraction problems, one with a single slit and one with a circular opening.
00:10
We'll do the single slit one first.
00:15
So we're asked to find x.
00:18
We're given that we have a single slit with width a.
00:22
We know our wavelength.
00:24
And we want to find out what x is when we know that m equals 3 for our order number.
00:34
Okay, so our formula is that m lambda is equal to a sine theta for a minimum.
00:49
That's what we're looking for.
00:52
And one thing we know from looking at the diagram is that we can use sine theta is equal to x over capital d.
01:03
We can do that because we know the angle is small.
01:08
So ultimately we want to find x.
01:11
We get a formula that looks like this.
01:14
M -lamda is a -x over d.
01:18
We can solve that for x is d -m -a.
01:28
And when i substitute all my numbers in, i find out that x is 0 .667.
01:40
And that gives us part a.
01:45
And now part b, we have a star or a pair of stars that are pretty far away.
01:56
And we know the distance between them is given as 4 .7 times 10 to the 11 meters.
02:12
And we're also told that when our telescope diameter is exactly 1 .06...