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Hi everyone, i'm here with problem 8 from chapter 7.
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In this problem, we have a radio tower that is giving off waves at a frequency of 93 meghertz.
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And we want to figure out what this frequency is equal to in wavelength.
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So how can we do that? well, first, let's take a look at our relationships.
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We know that these waves are traveling at a speed of 3 times 10 to the 8 meters per second.
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And that's the speed of light.
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And in this problem, we're also going to represent frequency as new.
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That is a v with the hook.
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And that's typically in hertz or 1 over second.
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And then we'll also represent wavelength as lambda, which typically looks like an upside -down y.
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And that's in meters.
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So now we have to relate these three things somehow.
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Well, if you notice, the speed of light is in meters per second.
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And we also have two other variables that can give us exactly meters per second.
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So now let's set up an equation where c, our speed of light, is equal to lambda times new.
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And if we write the same equation using their units, we'll find that this is also equal to meters times 1 over second, which is exactly what the speed of light is.
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And now we can rearrange this equation to give us the wavelength by taking c divided by new.
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And now we can plug in our known values, which is the speed of light, three times 10 to the eighth meters per second divided by the frequency, which is 93 megahertz...