AP Physics 2: 1.3 Waves

AP Physics 2: 1.3 Waves. How much farther away is the screen from the slits if the first bright fringe is now 2.2 cm from center?

AP Physics 2Waves
LanguageEnglish Language
Science Practice 4Using data collection strategies
Science Practice 5Performing data analysis

Transcript

00:25

cords and forgetting supplies and when he's finally done the fourth order

00:29

maximum is displayed 8 centimeters from the central bright spot just as he's

00:33

about to ask you students calculate something he knocks over the screen [Man knocks over screen]

00:36

displaying the interference pattern after a hasty restoration it appears to

00:41

be in a slightly different position but it's built perpendicular to the incident

00:44

light when the laughter subside mr. Klotz asks how much farther away is the [Students laughing and Mr Klutz asks question]

00:50

screen from the slit if the first bright fringe is now 2 point 2 centimeters from

00:55

the center and here are potential answers huh interesting question all

01:01

right let's got to be bad luck having with your clock is the last name it [People laughing at man]

01:05

would kind of determine your fate right like it's hard to imagine a CIA agent

01:09

named clutch or XM president clutch actually ever seen Gerald Ford now

01:14

professor klutz there well yeah that we can imagine okay [Professor walking on campus]

01:17

Young's double slit experiment helped show that light functions as a wave the

01:23

bright and dark spots that resulted from this experiment showed light waves

01:26

constructively and destructively interfering with each other

01:30

it helped show that light isn't a stream of particles the course later

01:33

experiments showed that light is a wave and is also a stream of particles but

01:38

let's get to this question because if we think too much about the wave particle [Girl reading book on dual nature of light]

01:41

duality of light our brain starts through West welcoming the pudding all

01:45

right there's a lot going on here so let's figure out what's important in

01:48

what we don't have to worry about in the double slit experiment there's a central [Double slit experiment set up appears]

01:52

bright spot than band of light or fringes in regular intervals or orders

01:57

going out from the center before mr. Klotz lived up to his name or maybe

02:02

that's professor klutz and not the screen over we saw that the fourth order [Man falls over]

02:06

maximum was 8 centimeters from the Center that means that on either side

02:10

from the center the fourth bright spot is eight centimeters away well after the

02:15

screen was set back up the first order maximum was two point two centimeters

02:19

from the middle point the distance of a maximum from the center equals the order [Man teaching]

02:24

number times the product of the wavelength and the length of the

02:28

distance from the slit to the screen over the distance between the two slits

02:33

there we go initially the equation would be for lambda L over V for the final [Equation appears on chalkboard]

02:38

position the equation would just be lambda L over D since we're dealing with

02:42

the first order maximum oh and we're using the approximate symbol because

02:47

when we're dealing with tiny numbers like the wavelength of light and the [Man with magnifying glass in classroom]

02:51

distance between the slit 8 centimeters is just too large a number to be precise

02:56

but it's just fine for our purposes here the only things that change in the setup

03:00

are the length of the distance from the slit to the screen and the order number

03:04

we're dealing with with a wavelength of light and the distance between the slits

03:08

aren't changing and like we said the bright fringe of the current regular

03:12

interval so if the fourth order fringe occurs at 8 centimeters the third order

03:16

fringe will be at 6 centimeters and the first order fringe will pop up at 2 [Order frames appear by slits]

03:20

centimeters which is good we like patterns we have an up randomness in

03:24

there live and we don't need more randomness and experiments as well well [Man drops plate]

03:28

looking at this is a ratio we can see that the ending length equals one point

03:32

one times the starting length that means to ending distance from the screen to

03:36

the fletcher's 10% farther than the original distance so the correct answer

03:41

is d and just remember science isn't always graceful and neither are

03:45

scientist Isaac Newton was always getting hit in the head after all that [Isaac Newton reading book and apple lands on head]

03:50

but then again Einstein helped create the art form we [Einstein dancing]

03:53

now call breakdancing