WEBVTT
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Our question says that we have a photo on of
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wavelength 589 nano meters and air that enters a crown
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glass with an index of refraction in equal the 1.52
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and it wants us to find the speed, wavelength
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and energy of the full time in the glass.
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So for part A to find this speed, we
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can use the fact that the index of refraction is
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defined as the speed of light in a vacuum,
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which is three times 10 of the eight meters per
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second, divided by the ah velocity, which that
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light is travelling in the glass. So if we
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saw for the Velocity V, we find that it's
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equal to the speed of light divided by the index
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of refraction planking those values. In this expression,
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we find that this is equal to one 0.97 times
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10 88 in the unit ear are, uh,
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units of velocity, which is meters per second weaken
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. Box it in as your solution. For part
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a part B asked us to find the wavelength of
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the photonic glass without wavelength. We'll call it Lambda
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Prime is going to be equal to the wavelength of
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the photon and air divided by the index of refraction
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in the glass. In plugging those values and for
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this expression we find that this is 387.5 or 388
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and the units here that we were using our nano
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meters and M, which is 10 to the minus
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nine meters. We can just leave in unit to
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Nana leaders, never part see were asked to find
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the energy of this photo on. Well, energy
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is equal to HC over Lambda, right? But
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the Lambda value that we want to use here is
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Lambda Prime. So for Lambda Prime, we use
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388 nano meters. But you need to use the
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meter's version of that. So it's 388 times 10
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to the minus nine meters. H year is planks
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constant at 6.63 times 10 to the minus 34 jewels
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. Time second, you can look up planks constant
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. You need thio and see here, of course
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, is the unit, huh? Ah, the
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speed of light. So this is five 0.13 times
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10 to the minus 19. Jules, so 5.13
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times 10 to the minus 19 jewels, which you
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could convert to electron volts. Just 3.2 electron volts
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. Lincoln Box set in as your solution for part
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C.