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1. Electrons Absorbing Photons - Extra Energy

objects are certain colours due to the fact that they REFLECT that colour of light. such that there phonons are opaque to that frequency. a photon is absorbed by an atom causing it to be excited and an electron moves to a higher energy state. photons will only be absorbed by atoms if they have...
2. A Newton Question

yes W is always the hypotenuse, so if u want to use the angle alpha then yeah Wx would be W cos alpha. this is exactly the same as W sin theta. always resolve the triangle like this. when its in the form shown in the book its harder to visualise as it makes it seem that Wx is the hypotenuse...
3. A Newton Question

W is always the hypotenuse due to it being the greatest value. imagine completing the vector triangle between W and Wx. the value at W would be theta from the original triangle
4. Acceleration confusion

you are trying to use constant velocity equation v=s/t instead of a constant acceleration equation here are the variables s=displacement, t=time, u=initial velocity v=final velocity a=acceleration here are the constant acceleration equations s=ut+0.5at^2 v=u+at s=(v+u/2)*t v^2=u^2+2as...
5. Fermi energy approximation for white dwarfs

where is the heat being produced in a white dwarf? I was under the assumption fusion had stopped.
6. Fermi energy approximation for white dwarfs

I believe it is due to the degeneracy pressure not allowing electrons movement. I just had a thought would the white dwarf act as a solid as such where it has energy bands instead of energy levels? is this why it glows white?
7. Wave theory of light

If you are refering to quantum theory then yes light is photons, but these are discrete energy packets and not a particle like a proton.
8. Wave theory of light

there are no particles, light is an electromagnetic wave, a wave consisting of an electric field and a magnetic field sloshing back and forth so to speak. if you are talking about "particles" being photons, photons have particle type characteristics and are discrete packets of energy not...
9. How to uniformly charge an insulating sphere?

is it not possible to uniformly heat the "insulating sphere" as to release conduction electrons?
10. Is potential energy real or fictious?

Isn't GR based on the thought experiment of a light clock? I'm pretty sure the effects of GR are "real".
11. Destructive Interference of gamma waves

Light is EM radiation, Gamma is EM radiation of high energy. If you were to induce interference with a single photon i.e. youngs slit experiment you will have constructive and destructive interference and a situations such as dale explained. Displacement is additive when talking about...
12. Electron changing energy state

So when thinking about the photoelectric effect we have to consider the properties of the material rather than a single atom that makes sense. I am not advanced enough for the Shrodinger equation i'm afraid. but I get what your saying I think. lol Thanks for the clarification Popper I was...
13. Electron changing energy state

When a photon is absorbed by an electron the electron moves from ground state to a higher energy lets say n=3. this electron can then drop back down and emit a photon of the exact energy as the photon that was absorbed. My question is why is there no work function or energy transfer as it...
14. Sun Diffraction

If you use a white light bulb you should get a diffraction pattern where the central minima is white as the path difference is the same for each wave. The other maxima will be of different colours due to different path lengths and white light being made up of different wavelengths of light. I...
15. Destructive Interference and coherent light in anti-phase

thanks jtbell and sophie the explanations are very clear and make perfect sense. Is it known how this energy transfers from one wave to another?
16. Destructive Interference and coherent light in anti-phase

Thank you very much Dale, I feel I have a greater understanding now. :smile:
17. Destructive Interference and coherent light in anti-phase

Say a wave was sent through a waveguide one of length being an integer of the wavelength and the other being a non integer value, this produces destructive interference and a wave with a lower amplitude giving less intensity and energy, in this scenario there are no other waves present where has...
18. Destructive Interference and coherent light in anti-phase

Thanks Sophie, I was actually thinking about the double slit experiment. Could you possible expand on this point:
19. Destructive Interference and coherent light in anti-phase

I have a question about coherent light in anti-phase, I'm probably thinking about this wrong but I just cant understand what happens to the energy in the wave when two waves of the same wavelength, frequency and amplitude are in anti-phase as the resultant wave is 0.
20. Light as a wave

I will see if i can find that book anywhere! My OCR book has a picture of the sun on the front of it so i'm guessing it has changed. i plan on doing this work as extra over summer as i want to revise from now until the exams.
21. Light as a wave

I am doing the OCR physics and the text book is useless. it just tells you the basics for the exam and no real explanation, a lot of the information in it i find useless its only used for definitions and formula. also my teacher is a good teacher, very nice explanations but he only really knows...
22. Light as a wave

yeah I have only read popular science books about QM and things on the internet. You made a funny! so I guess i need to find a textbook to read over summer. Im guessing i will need a book on the maths used to accompany it too.
23. Light as a wave

I know theories and concepts of some areas of QM but none of the maths, I have no idea about tensors or matrices. I have been trying to find a book to read on QM which would make some sense but have been unable to find one. Could you recommend a book on QM and on light that will broaden my...
24. Light as a wave

Sophie, I must admit the education system in England is AWFUL, I wish to learn of superposition and other QM theories yet i am taught incomplete classical mechanics which discourages me to work. i have read QED by Feynman, amazing book with so much insight the guy is a genius and E=mc^2 by brian...
25. Light as a wave

Thanks Drakkith. When talking about light as photons how does one show this graphically? is a displacement/time graph still used? and what would it look like?
26. Light as a wave

Thanks for the replies. He was not talking about antennas just light, I knew he was teaching it wrong. My mistake I did not mean 45 degrees I meant perpendicular.
27. Light as a wave

I am currently studying AS level physics and we have just started the waves module. When describing light as a WAVE our teacher is telling us that particles are oscillating 90 degrees to the propagation of the wave. What is acting at right angles to the propagation of the wave? As far as i was...
28. Energy level after photon absorbtion

so how does the electron know that the photon does not have enough energy to move it to a free orbital?
29. Energy level after photon absorbtion

Say a photon was absorbed by an electron at 1s in an oxygen atom but it only had enough energy to move it to another energy level that was already occupied such a 2s etc. What happens to this photon?
30. White light and how it works

Drakkith, so photons from each wavelength hit the eye at roughly the same time making white light, I believe I nearly had the answer just I thought they travelled as a collective. Thank you drakkith