Wavelength Definition and 1000 Threads

According to simple math you get \lambda=h/p for photons. and the assumption is for everything else, whilst for everything else which is NOT restmass=0 it should be \lambda=hc/E. So why is it referred to as simple \lambda=h/p when clearly it is not true mathematically. It would be true for...

[b]1. question [b]2.hello Dear , I have a question for you please , When you buy a home cinema system, you can place the subwoofer almost anywhere, even behind your couch. But the tweeters (speaker for high frequencies) must be placed very accurately. Explain why! Hint: use...

How the wavelength of wave is measured? My idea of electromagnetic wave is there is an invisible line traveling through space moving up and down like a sine wave we see on CRO. Is this idea correct? Or is it the the variation in electric and magnetic field of the wave that we relate this...

Homework Statement An electron with energy 10^3 MeV collides with a photon whose wavelength corresponds to the maximum wavelength of the 2.7-K cosmic background radiation. What is the maximum energy loss the electron can suffer as a result of the collision? What is the wavelength of the photon...

6. http://i111.photobucket.com/albums/n149/camarolt4z28/2010-09-23195548.jpg?t=1285299756 I'm thinking I use the omegaij formula to determine the frequency between energy levels and then use that to calculate the wavelength...

Homework Statement Determine the wavelength (in nm, to one decimal place) of the line in the emission spectrum of the He+ ion produced by a transition from n = 3 to n = 1. Homework Equations I used the Rydberg equation for this, although I'm not sure it is the correct one to use...

Homework Statement By estimating the De Broglie wavelength and the inter-particle spacing, find whether the following systems of particles are degenerate: (i) a gas of neutrons in a neutron star with mass density 10^17 kg/m^3 at the temperature of 10^8K (ii)a gas of oxygen molecules at...

Homework Statement Show that the de Broglie wavelength of a particle of mass m and kinetic energy KE is given by \lambda = \frac{hc}{\sqrt{KE(KE + 2mc^2)}} Homework Equations The Attempt at a Solution I know: KE = {\gamma}mc^2 - mc^2 = pc - mc^2 But from here I am...

If a theoretical single photon followed a geodesic toward a large mass in space, I understand that the wavelength would shorten as it approached the mass. How would the energy be conserved within the photon, because the frequency must surely remain the same?

Wikipedia: Does the wave theory itself (the mathematical formulation) imply that diffraction is more efficient at longer wavelengths? I just want the logical connection of why (for example) radio waves diffract and bend around objects better than visible light. :confused: Thank you.

Homework Statement I'm not even sure the problem is about matterwave: A particle of mass m and charge e is accelerated by a potential difference V. Find the wavelength of the particle. Show that this result agrees with the classical one when the non relativistic limit is taken.Homework...

Homework Statement An x-rays tube is connected to a 50 kV emf. Calculate the minimum wavelength that one can find in the radiation spectra that the tube produces.Homework Equations No idea! This is why I ask help here. The Attempt at a Solution Stuck at start. I've searched in google and...

here are the problems that I need help with: http://imgur.com/a/fERMC/1 I am afraid that I know not much information about the questions. Sadly, I am enrolled in a poorly written Physics class online. I am not looking for the answers, but just how to go about finding them. The book never...

We've got a table of periods (in seconds) and their corresponding wavelengths for creating resonance in a closed pipe. I've been told that plotting a graph of period (on x axis) vs wavelength, and finding the gradient of that linear line will tell me the speed of sound in air. I can do that...

Hi, "Somebody makes a noise with a frequency of 1000Hz. Calculate how long it will take to reach somebody 3m away. What will be the wavelength?" I can't figure out how it fits into any of the formulas I have! Thanks! :)

Homework Statement An electron beam (energy 119,9 eV) contacts perpendicularly on a Ni plate, with interatomic spacing d= 0,215 nm. At which angle Theta will be obtained an electron beam with the lower wavelenght possible? Homework Equations n\lambda=d sin(\theta) (Bragg's for...

E=mc^2 and E=hf. In Special Relativity, how can y=h/p be derived from E=hf?

Is there any lower limit on the frequency of electromagnetic radiation? I imagine that beyond a certain frequency it becomes impossible to detect, but is there anything in the maxwell equations that establishes a maximum wavelength (besides the limits of the size of the universe)? Thanks

Homework Statement In his presentation of the de Broglie wavelength and the wave/particle duality, my quantum prof. has an exercise: "Find the de Broglie wavelength of a molecular vibration. Do quantum or classical laws apply?" Homework Equations wavelength = h/(momentum) ...

1. Astronomers on Earth observe a feature at 442 nm in the spectrum of a distant quasar. However, it is known that this feature corresponds to 581 nm in the rest frame of the quasar. Calculate the speed of the quasar. Enter your answer as a fraction of the speed of light, positive if the quasar...

The maximum wavelength for blackboby radiation is .29/Temperature. Is the average wavelenght 1.84 times the maximum for all temperatures?

I've gotten curious about how the human eye's sensitivity to long wavelengths drops off. What's the longest wavelength anybody has ever seen? I know there is nonzero (but very low) sensitivity to 800+ nm light, but does anybody know the extreme long wavelength limit of human vision?

Homework Statement Electron and positron each have a kinetic energy of 220 keV even when far apart. Homework Equations The Attempt at a Solution I have no idea. My book says the answer 1.46 MeV, 8.49 x 10^-13 m but I don't know how to get that.

Hi, Why are mass and wavelength are inversely proportional?

I've been searching on this topic for the past 10 minutes and then realized it'll be better just asking someone about it. Anyway yeah, the question is, are there any specific equations that will give me the wavelength when I give it the colour values? I saw some sites where each colour in the...

Why are short wavelengths (of e.m. radiation say) required for observing the location of a small particle? Classically, I could imagine sending a wave train of light (or a photon) of different frequencies onto an atom in free space. Providing the electrons in the energy levels of the atom can...

Hello, I've always wondered about the "relativity" of the De Broglie wavelength. The wavelength depends on the momentum of the specific thing we are observing, thus on different frames of reference(F.O.R from now on :P) we might get different answers. I have been looking through the web to...

Homework Statement Parallel beam of "cold" neutrons in the x-axis, with energy 0.1eV strikes a slit system in y-z plane. Slits are parallel to the y-axis 1 micron apart. What will be the distance between the detector at x=20m which records the highest flux of neutrons, and the closest one...

Homework Statement Two of the wavelengths emitted by a hydrogen atom are 9.50×10-8 m and 4.65×10-6 m. What are the m and n values for the first wavelength? Homework Equations E = -13.6eV/n2 E = -13.6eV/(m2 - n2) restriction:m > n E = hf f = c/λ 1 eV = 1.6 x 10-19J The Attempt at...

I am creating this wavelength chart (attached). I was told to use Compton's formula; I got this: (6.626068 × (10^(-34))) / (1.1542e+42 * 299 792 458) = 1.91493535 × 10-84 Apparently, it is substantially off scale. I was then told to try de Broglie wave. Wikipedia only shows relations...

It there a smallest possible wavelength? And if there is, what is that wavelength?

it has been a while. i need to know which wavelength is bigger FM radio or Am radio?

Homework Statement Calculate the de Broglie wavelength of an oxygen molecule (molecular mass 32)in air at room temperture. Homework Equations P = h/ \lambda P= mv E= hv = 1/2mv^{2} = P^{2}/(2m)The Attempt at a Solution hv = 1/2mv^{2} h = 1/2mv If v = P/m then h = mp/2m so p= 2h This...

can anyone tell me the meaning of frequency and wavelength of photon.what exactly it indicates?As it is particle then how it can have frequency and wavelength?frequecy is charaterstics of wave.

This question relates to the design of a Tesla coil, which is basically a loose-coupled, tuned transformer. The secondary is a series LCR circuit that develops a high voltage across a capacitor. The capacitor takes the form of a toroidal 'top-load' to ground. In the literature, much...

Could electromagnetic wavelength be used as a legitimate distance pattern? I mean is it OK to exchange geometrical length with physical wavelength? For example, given a bundle of light rays following geodesics in empty space, can the length between a given pair of geodesics be equivalent to a...

What kind of electromagnetic radiation can carry more information?. I mean, what is the relation between shorter or longer wavelength and the information that can go within. I wonder how the dynamics of this process works, considering that sound waves also can carry information, as well every...

I can work out the wavelengths fine, but I am unsure of the answer to the second part, any help would be much appreciated

Homework Statement what is the physical significance of wavelength (not the definition)? Homework Equations suppose, in photodetectors (like avalanche or p-i-n photo diodes) incident light having more wavelength, penetrates more in the diode (particularly in depletion region : )...

Can anyone tell me what frequency and Wavelength Radar and Sonar work in. I think Radar have a frequency of 300giga hertz (UHF), wavelength 0.1 Sonar is somewhere between wavelength 100k - 10k metres, frequency 3k - 30k hertz. Please help me thanks,

Homework Statement The wavelength of an electron is 4.4 × 10−7 m. How fast is it moving? The Planck’s con- stant is 6.62607 × 10−34 J · s . Answer in units of m/s. 013 (part 2 of 2) 10.0 points If the electron has a speed of 9 × 106 m/s, what is its wavelength? Answer in units of m...

hi, my exam is tomorrow and I really need to understand this. Imagine a region of constant gravitational field, directed "downwards". There is a photon traveling in this downward direction. There are two observers, A and B. At t=0, they do not have any relative velocity. However, B is fixed...

Just curious, what is the longest wavelength we can currently observe with our instruments, & are there are good sources for future (even if just theoretical) projects at longer wavelengths (future projects do no have to be based on Earth)?

I'm doing OCR A-Level Physics, and in my textbook it states "They (Penzias and Wilson) made a calculation to find the temperature of the source of the radio waves, which had a maximum intensity at wavelength 1.1 cm, and found it to be 2.7K". This was all good and well, until I answered a...

Homework Statement A car is traveling at 30m/s in still air. the frequency of the siren on the car is 600hz. The velocity of sound in still air is 330 m/s. what is the wavelength of the sound waves a)directly in front of the car b)directly behind the car What is the frequency of the...

Homework Statement Find the wavelength of the radiation emitted when a hydrogen atom makes a transition from the n = 6 to the n = 3 state. Give answer in µm. Homework Equations z^2 / n^2 x 13.6ev delta E = E2 - E1 = hv The Attempt at a...

As is well known, Planck's radiation law for the distribution function of blackbody radiation used a then new concept of energy quanta in order to describe experimental data. The distribution functions formulated by Wilhelm Wien and Lord Rayleigh, describing the same phenomena, were...

Homework Statement A surface of a substance has a work function of 2.24 eV. (a) What is the maximum kinetic energy of ejected electrons if the incident radiation is of wavelength 419 nm? eV (b) What is the threshold wavelength for this surface? nm Homework Equations E=hf...

Hey guys and girls, I'm having a hard time trying to start this problem. I think I have an idea of what to do to start it, but I'd like someone to verify it for me: Homework Statement A mass, m = 5.50kg hangs from a cord around a light pulley. The distance between point P and the pulley...

i think its to do with huygens sources?