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Here's your shmoop du jour brought to you by classes luckily we're

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not clutches we're as graceful as a ballerina [Ballerina girl dancing]

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well ballerina with a concussion all right mr. klutz a teacher in part-time [Ballerina falls on the floor]

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rodeo clown sets up a demonstration of Young's double-slit experiment in class

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it takes almost 2 hours because he keeps dropping things tripping over power [Mr Klutz drops item]

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

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

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

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displaying the interference pattern after a hasty restoration it appears to

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

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

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

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the center and here are potential answers huh interesting question all

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

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

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

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

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

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

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constructively and destructively interfering with each other

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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now call breakdancing

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