Optics B/C

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blue cobra
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Re: Optics B/C

Postby blue cobra » March 1st, 2012, 9:10 am

I can't seem to get the hang of Doppler effect problems. Could someone please guide me through an example?
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Re: Optics B/C

Postby foreverphysics » March 1st, 2012, 11:20 am

All right. Say you have this problem:
A train is moving directly towards you at 2×108 m/s. The (monochromatic) light on the front of the train has a wavelength of 250 nanometers in the frame of the train. What wavelength do you observe?

I will post answer and how-to-solve later, because there are...ah...things on my computer that are preventing me from doing that at present moment. I would like you to try your hand at solving it first, anyhow.

Equation (if it shows up right):
Image
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Re: Optics B/C

Postby hexagonaria » March 1st, 2012, 11:37 am

Schedule conflict.. Goodbye optics :cry:
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Re: Optics B/C

Postby Osennecho » March 1st, 2012, 11:52 am

Is there a difference between red glass and a red filter? Essentially, does red glass filter red light in the same way that a filter would. I know stained glass would but I am not sure about the more general term glass.. I hope I made that question clear enough to understand.
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2012 Events: (Regionals, States, Nationals); N/A=conflict
Astronomy (6th, 7th, 16th)
Dynamic Planet (N/A, N/A, 11th)
Optics (2nd, 3rd, 5th)
Remote Sensing (N/A, 5th, 47th)

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Re: Optics B/C

Postby SciBomb97 » March 1st, 2012, 12:02 pm

Well, I think it's that red glass reflects and transmits only red light, and a red filter just takes the red wavelengths of light in the light that passes through it.
That reminds me of the emission/absorption spectrum thing.
Schedule conflict.. Goodbye optics :cry:
Me too, and if we make it to nationals, it conflicts with the same event at nationals too...
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Re: Optics B/C

Postby foreverphysics » March 1st, 2012, 12:54 pm

I'm screwed. My partner knows nothing. So, so, so screwed...
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Re: Optics B/C

Postby blue cobra » March 1st, 2012, 1:49 pm

All right. Say you have this problem:
A train is moving directly towards you at 2×108 m/s. The (monochromatic) light on the front of the train has a wavelength of 250 nanometers in the frame of the train. What wavelength do you observe?

I will post answer and how-to-solve later, because there are...ah...things on my computer that are preventing me from doing that at present moment. I would like you to try your hand at solving it first, anyhow.

Equation (if it shows up right):










or with sig figs



That's assuming I punched that beast into my calculator correctly :lol:
I knew that equation, but when I tried it out elsewhere I got the wrong answer. Is v positive or negative when the source is approaching? Either way I got the wrong answer on the example I did...
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Re: Optics B/C

Postby chalker » March 1st, 2012, 2:59 pm

Schedule conflict.. Goodbye optics :cry:
Me too, and if we make it to nationals, it conflicts with the same event at nationals too...
Which event is in conflict? We try to setup to schedule so events the same student is likely to compete in don't overlap (but obviously can't account for all possible overlaps)

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Re: Optics B/C

Postby SciBomb97 » March 1st, 2012, 3:04 pm

Schedule conflict.. Goodbye optics :cry:
Me too, and if we make it to nationals, it conflicts with the same event at nationals too...
Which event is in conflict? We try to setup to schedule so events the same student is likely to compete in don't overlap (but obviously can't account for all possible overlaps)
For me, optics conflicts with microbe.
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Re: Optics B/C

Postby himynameis » March 1st, 2012, 5:14 pm

How would you go about writing the programs for a TI-84 calculator?


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