Optics B/C
-
- Exalted Member
- Posts: 417
- Joined: Thu Apr 09, 2009 6:10 pm
- Division: Grad
- State: NY
- Has thanked: 0
- Been thanked: 0
Re: Optics B/C
I can't seem to get the hang of Doppler effect problems. Could someone please guide me through an example?
In full color since 2006
-
- Moderator
- Posts: 497
- Joined: Fri May 20, 2011 8:41 pm
- Division: Grad
- State: AL
- Has thanked: 0
- Been thanked: 68 times
Re: Optics B/C
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):![](http://latex.codecogs.com/png.latex?\frac{f_s}{f_o} = \sqrt{\frac{1+\beta}{1-\beta}})
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):
-
- Member
- Posts: 24
- Joined: Thu Dec 23, 2010 8:17 pm
- Division: Grad
- State: PA
- Has thanked: 0
- Been thanked: 0
Re: Optics B/C
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.
Last edited by Osennecho on Thu Mar 01, 2012 12:02 pm, edited 1 time in total.
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)
Team Overall (3rd, 2nd, 14th)
It's been a life changing 6 year experience.
Astronomy (6th, 7th, 16th)
Dynamic Planet (N/A, N/A, 11th)
Optics (2nd, 3rd, 5th)
Remote Sensing (N/A, 5th, 47th)
Team Overall (3rd, 2nd, 14th)
It's been a life changing 6 year experience.
-
- Member
- Posts: 185
- Joined: Tue Dec 06, 2011 9:22 pm
- Division: C
- State: AL
- Has thanked: 0
- Been thanked: 0
Re: Optics B/C
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.
That reminds me of the emission/absorption spectrum thing.
Me too, and if we make it to nationals, it conflicts with the same event at nationals too...hexagonaria wrote:Schedule conflict.. Goodbye optics
-- -- --
"So whether you eat or drink or whatever you do, do it all for the glory of God." ~1 Corinthians 10:31~
They say that a smile can light up somebody's day
So today, smile
Shine a light in somebody's life
Be that light in the darkness
"So whether you eat or drink or whatever you do, do it all for the glory of God." ~1 Corinthians 10:31~
They say that a smile can light up somebody's day
So today, smile
Shine a light in somebody's life
Be that light in the darkness
-
- Moderator
- Posts: 497
- Joined: Fri May 20, 2011 8:41 pm
- Division: Grad
- State: AL
- Has thanked: 0
- Been thanked: 68 times
-
- Exalted Member
- Posts: 417
- Joined: Thu Apr 09, 2009 6:10 pm
- Division: Grad
- State: NY
- Has thanked: 0
- Been thanked: 0
Re: Optics B/C
foreverphysics wrote: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):
That's assuming I punched that beast into my calculator correctly
![Laughing :lol:](./images/smilies/icon_lol.gif)
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...
In full color since 2006
-
- Member
- Posts: 2107
- Joined: Fri Jan 09, 2009 7:30 pm
- Division: Grad
- State: OH
- Has thanked: 1 time
- Been thanked: 56 times
Re: Optics B/C
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)SciBomb97 wrote:Me too, and if we make it to nationals, it conflicts with the same event at nationals too...hexagonaria wrote:Schedule conflict.. Goodbye optics
Student Alumni
National Event Supervisor
National Physical Sciences Rules Committee Chair
-
- Member
- Posts: 185
- Joined: Tue Dec 06, 2011 9:22 pm
- Division: C
- State: AL
- Has thanked: 0
- Been thanked: 0
Re: Optics B/C
For me, optics conflicts with microbe.chalker wrote: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)SciBomb97 wrote:Me too, and if we make it to nationals, it conflicts with the same event at nationals too...hexagonaria wrote:Schedule conflict.. Goodbye optics
-- -- --
"So whether you eat or drink or whatever you do, do it all for the glory of God." ~1 Corinthians 10:31~
They say that a smile can light up somebody's day
So today, smile
Shine a light in somebody's life
Be that light in the darkness
"So whether you eat or drink or whatever you do, do it all for the glory of God." ~1 Corinthians 10:31~
They say that a smile can light up somebody's day
So today, smile
Shine a light in somebody's life
Be that light in the darkness