Wavelength Definition and 1000 Threads

Hey all, A physics example I'm working on to do some studying. The example is as follows: What is the wavelength of the scattered photon when a free electron (initially stationary) acquires maximum energy in a collision with a photon of energy 4 x 10^3 eV? My problem is this: it seems...

The de broglie wavelength is h/p, where p is momentum, and hence mv, so wavelenght = h/ (mv). The mass is on the denominator, so a massive object, like a baseball, will have a small wavelength, beyond detection and we can ignore it. OK, so does the mass have to be moving to have a de broglie...

What is the relationship wavelength and group velocity in wave packet ? If a wave packet has big wavelength its group velocity bigger or not ?

Homework Statement When light is frequency 2,00 x 10(in 16force) Hz prostrate a metal surface electrons are abstracted with kinetic energy 7,50 x 10(in -18force) J. Calculate: (a) The frequency v0 for the metal (v0: the minimum frequency of light, below which no electrons emitted). (b)...

Homework Statement A Michelson interferometer is operated in a vacuum, using monochromatic light of wavelength 589 nm. The interferometer is set up so that the distances between the moving mirror and the beam splitter and the fixed mirror and the beam splitter are equal. A parallel-sided...

Homework Statement The portion of a piano string between the bridge and upper end of the finger board is 0.50 meters long. The string when plucked sounds a note of 440Hz- the first harmonic. a. where must the violinist put a finder to pay a C note- 528Hz b Without returning, is it possible...

Homework Statement Light of wavelength 0.544 µm (in air) enters the water in a swimming pool. The speed of light in water is 0.700 times the speed in air. What is the wavelength of the light in water? Homework Equations mu = m / L v = sqrt (F/mu) speed of air 386 m/s The Attempt...

Finding index of refraction using wavelength and 2 angles?? I'm not sure how to do a problem that involves a light ray striking a block/air interface, how to find the index of refraction of a transparent material when given the wavelength, the angle the light ray makes with respect to the...

Hi! I really need some help I'm really really not good at physics...so Here it is 1) The electron energy of a hydrogen atom is given by -C/n^2 relative to zero energy at infinite separation between the electron and the proton (n is the principle quantum number, and C is a constant). For...

According to our lab manual, the graph of Wavelength vs Period : the slope should be the speed of sound. Well, I have a negative slope of -32.2 which is ridiculous, but I can't find out what I'm doing wrong. We had 5 tuning forks , say for instance, 512Hz...the inverse 1/f = 1/512= 0.00195 , I...

What property of visible light defines its color, the wavelength or frequency (or something else)?

Homework Statement If the maximum energy imparted to an electron in Compton scattering is 45 keV. What is the wavelength of the incident photon? Homework Equations The Attempt at a Solution \lambda_2 - \lambda_1 = h/mc (1 - cos \theta ) My first initial thought was to apply...

Homework Statement A 220lb fullback runs the 40-yd dash at a speed of 19.6 ± 0.1 mi/h. What is he de Broglie wavelength (in meters)? Homework Equations de Broglie Wavelength: λ=h/(mu), where λ=wavelenght, h=6.626 x 10^(-34) kgm^2)/s, m=mass (kg), and u= speed The Attempt at a...

I'm sorry if this is the wrong forum but in a problem I was given wavelength with the unit as an A with a circle above it, can anyone tell me what this means and how I can get it into more familiar terms (meters, for example)?

Homework Statement A photon whose energy is 8.00E-15 J is scattered off an electron at a 90 degree angle What is the wavelength of the scattered wave? Homework Equations i know that Lamda = hc/E =6.63E-34 * 3E8 / 8E-15 =2.48E-11m The Attempt at a Solution Does anyone know how...

Homework Statement The element Be has 4 electrons and 4 protons in the atom. An ion of Be has all the electrons removed except 1, so it resembles a hydrogen atom with a nuclear charge of +4 e. Constants: E1(Hydrogen)= -13.6eV, r1(Hydrogen)= 5.29x10-11m. If a gas is made up of ions...

What has been the longest photon wavelength actually observed?

If you are told that a silver surface is irradiated with light having a wavelength of 230 nm that causes electrons to be ejected with 77.67 kJ/mol of kinetic energy, how would you find the threshold frequency? I know that threshold frequency = W / h. W is the work function and h is...

Homework Statement Calculate the de broglie wavelength (DBW) of an electron with kinetic energy 60 GeV. What percentage of an atom's diameter can it penetrate? Homework Equations DBW = h/p p=mv The Attempt at a Solution Basically I have an electron traveling at the...

Re the article by Bojowald in the October issue of Scientific American about Loop Quantum Gravity. He states that one of the consequences of the theory is that the speed of light is a function of wavelength. Any experimental evidence, or even hint of evidence, that anyone knows of?

Homework Statement Light passes through a 200 line/mm grating and is observed on a 1.0 m wide screen located 1.0 m behind the grating. Three bright fringes are seen on both sides of the central maximum. What are the minimum and maximum possible values of wavelength? Homework Equations...

What is the thinnest film of MgF2 (n = 1.39) on glass that produces a strong reflection for light with a wavelength of 680 nm? This is the exact question I am faced with. I didn't really know where to begin so I tried using the ratio of n-air/wavelength to n-film/(new wavelength) to try and...

If the primary germicidal UV wavelength is 270nm and the secondary is 254nm and I have a UV light source in air to provide germicidal effects in water, would the wavelength of the UV light source need to be 360nm and 338nm respectively assuming the index of refraction for water to be 1.33?

Homework Statement We learn from school that when we shine white light through a prism, dispersion occurs. This is because the light of varying wavelengths are refracted to a different extent due to how refractive index varies with the wavelength of light. So why does refractive index vary...

Hello everyone, I just want to ask a question. If higher the amplitude the particles move a larger distance right. So is the wavelength related to amplitude. The sound travels in circles right. So I'm bit confused here how they travel in circles and be a longtitudinal wave at the same time. Any...

A wave with a frequency of 190 Hz and a wavelength of 26.2 cm is traveling along a cord. The maximum speed of particles on the cord is the same as the wave speed. speed = wavelength X frequency

I had a go at 2 Q's and wanted to make sure I'm doing this right. so here's the first one, and maybe if i went wrong with it I was going to redo the 2nd Q on my own. \lambda = h/p = h/mv (\sqrt{1-((v^2)/(c^2))}) so, an Alpha Particle traveling @ 2x106m/s (mass = 6.645x10-27 kg)...

This has bugged me for a while; In CD's for example the wavelegth of the laser is the limitng factor of the amount of data because of the spot size it makes. The spot size is diffraction limited, so the smaller the wavelength the smaller the allowed spot, OK so far. But when we are talking...

Hi all, My question is, does the radius of a star vary significantly between different wavelengths? I am particularly interested in the 100 nm to 100 micron range. I found a paper by Paul Swanson on the radio band radius, but so far can find nothing which compares optical and infrared...

Helium becomes a super°uid at temperatures T < 2:18 K. A super°uid °ows with no viscosity. This behaviour can only be explained using quantum physics and it can only happen if the de Broglie wavelength of a helium atom, of mass m, is comparable to the inter-atomic spacing of the °uid. What...

Homework Statement An electron has a de Broglie wavelength of λ = 6.4e-10m. What is its speed? What voltage was needed to accelerate to this speed? Homework Equations v=h/mλ KE = 1/2mv^2 The Attempt at a Solution I already determined that the speed is 1.136e6 m/s. Finding the...

Homework Statement The work function of zinc is 4.31eV. What is the maximum wavelength of light that will cause electrons to be emitted from a zinc surface? Homework Equations I'm not sure because, we are given the Work Function (W) which is 4.31eV and we need to find the max. wavelength...

A wave travels with speed 200m/s. Its wave number is 1.5rad/m. What are its wavelength and frequency? distance = wavelength x # of wavelengths v=lamda(f) 1m = 1.5 (lamda) since in 1 meter there was 1.5 waves. 1/1.5 = 0.66m 200 = 0.66 (f); f = 300Hz. But this is wrong. I don't know...

Homework Statement a ski gondola is connected to the top of a hill by a steel cable of length 620m and diameter 1.5cm (r=.015m) As the gondola comes to the end of its run it bumps into the terminal and sends a wave pulse along the cable. It is observed that it took 16 s for the pulse to...

A standing wave resonates at 400 Hz with three antinodes on a string tied tightly between two posts 2.0 meters apart. What is the wavelength of this standing wave? What is the fundamental frequency of this string? I tried to draw the picture out, and it looks like the wavelength is just...

Homework Statement An electron moves in the x direction with the de Broglie wavelength 10^-8 cm. a) What is the energy of the electron in (eV)? b) What is the time-independent wavefunction of the electron? Solution? a) We have p = h/2pi * k = h/2pi * 2pi / lambda. So, p = h /...

I often see the charge radius of a proton at .8 * 10^-15m. An acquaintance on a different forum said he would use, if asked to determine the radius of a nucleus, to be: R = R0 * A^(1/3) where R0 = 1.2 * 10 ^ -15 to 1.5 * 10 ^ -15 and A is number of nucleons. He cited the sources...

I've been working on problems trying to find the dispersion relation of monatomic and diatomic chains. I'm able to find the dispersion relation, but I don't really understand what it is. I'm pretty sure that it's the relation of the frequency to the wave vector. I'm working through Kittel's...

There are two equations I know of that link velocity and wavelength: 1 velocity = frequency x wavelength 2 de broglie wavelength= Planck's constant/ (mass x velocity) I read that 'When particles are accelerated to high velocities, they have low wavelengths'. This means that...

Hello there, For the following problem, I am arriving at an answer different from the given one so I would appreciate any help or hints. Thank you. My work is shown below. --- 1. A slightly smaller plastic pipe is inserted inside a second plastic pipe to produce an air column, open at both...

Ok so i got this problem in my physics textbook and I'm just struggling with the last part, please help X-rays are detected at a scattering angle of 163 and have a wavelength of 0.1867 nm. Find (a) the wavelength of an incident photon, (b) the energy of an incident photon, (c) the energy of a...

[FONT="Georgia"][SIZE="3"]Homework Statement [FONT="Georgia"][SIZE="3"]The speed of light is 3 \times 10^8 ms^{-1}. Calculate the frequency of red light of wavelength 6.5 \times 10^{-7} m. Homework Equations v = f\lambda f = \frac{v}{\lambda} The Attempt at a Solution v = 3 \times 10^8 \...

Relativistic or Classical?? Calculation of De Broglie Wavelength Hi there, Okay, the question is: Calculate the De Broglie Wavelength of a 10 MeV proton and a 1 MeV electron. How does one know whether to use relativistic or classical means? Relativistic => Kinetic / Rest mass >/ = 10%...

How do you calcuate at what energy do a photon and an electron have the same de broglie wavelength?

1. At what speed is an electron's de Broglie wavelength: (a) 1.0 pm (b) 1.0 nm (c) 1.0 \mum (d) 1.0 mm2. \lambda = \frac{h}{mv} 3. I have solved for v, and I plugged in values, it gives me, for a = 4.54 x 10^(27) m/s, the ANSWER is: 2.77 x 10^(8) ms, it's way off, I tried converting energy into...

All the below is presented in latex format. In Schroeder's intro to thermal, problem 7.38, he asks you to substitute \lambda = \frac{hc}{\epsilon} into the following equation \frac{U}{V} = \int^{\infty}_{0} \frac{8 \pi \epsilon^{3}/(hc)^{3}}{e^{\epsilon / kT}-1} d \epsilon...

[SOLVED] [Multiple Choice] ...wavelength of an object. de Broglie wavelength 1. THE PROBLEM STATEMENT MULTIPLE CHOICE Which of the following would you expect to have the largest wavelength associated with it? (A) a quick-moving bee (B) an electron orbiting a nucleus (C) a slowly lumbering...

Homework Statement Imagine that you are in a vehicle at night on a long straight road. There are no streetlights and one vehicle up ahead in the distance. Estimate how far away the other vehicle would be for its tail-lights to appear as a single orange/red blob. In your answer, make...

Hi all! I just joined the forums and hopefully my question is in the right place and isn't a lame one but I'm stuck so here goes: I want to know how to calculate wavelength from a known distance and color for Helium. I need exact wavelength. I already have the ranges obviously. Usually...

[SOLVED] Finding KE when given de Broglie wavelength Homework Statement What is the kinetic energy, in MeV, of a proton with a de Broglie wavelength of 10fm? 1 MeV = 10^6 eV 1 fm = 10^-15m 1 eV = 1.602 x 10^-19 J h = 6.63 x 10^-34 Js wavelength = 10 x 10^-15 m = 10^-5 nm Mass proton =...