00:01
Let's just begin solving problem 22.
00:03
First of all, let's set it up.
00:15
So we have parallel rays passing through to slith.
00:20
The wavelength of the light is lambda equals 500 nanometers.
00:29
And the distance between our slid to the screen, we call that x, it equals 90 centimeters.
00:42
We don't know the slid with a here.
00:48
We don't know and we also don't know separation between the two sleeves which is called d.
00:59
Also we don't know.
01:02
What we learn is the rays pass through those sleeves and they will form some pattern there.
01:20
Basically those patterns are the diffraction patterns.
01:24
Combined with the interference patterns.
01:29
So if there are, or say if the, they are just interference, what we may have is this, this intensity of light.
01:52
But if we just have the diffraction or say there, if there are just one single sleeve there, instead of two sleeves, what do we have, maybe, is approximately something like this.
02:15
Okay, now, if we have both, what will happen? in this case, a slit with a is comparable with the separation d.
02:28
They are almost at the same level of the quantity.
02:32
So the final result of the pattern will be something like this, something like this.
02:55
Yes, it looks like just like the interference pattern was confined by the green curve, was confined by the diffraction pattern.
03:09
So that's the basic physics of this.
03:15
From the problem itself, we learned that the bright pattern distance between, i mean, the peak from here to here it's our y here it's r y it's one centimeters okay that's right down here so um now this is set up with this problem okay let's just go back and try to initialize every variables and now we begin to apply the equations we learn from this chapter and the previous chapter about the interference, and then i get the calculation.
04:24
So the problem side, the third brightness band is missing on both sides, which means the third bright band is missing because of the first order single sleeve minimum occurs at the same angle and the third order double speed maximum.
04:51
So from the equation 36 .8, we learned that we have a slit with a times sine theta.
05:04
It equals m times numbed.
05:09
And from the equation in chapter 35 about the interference, we learned that separation d times sine theta equals capital m is lumped...