Energies Definition and 314 Threads

Just a quickie. For example, the total kinetic energy of N molecules is = (3/2)NkT = (3/2)nRT If a question were to ask you to find the such energy for a sample of N_{2} would it make the equation (5/2)kT? Does the subscript 2 make it diatomic, and hence have two molecules, I am not sure...

Hi: In experimental HEP, Why are higher energies associated with shorter distances , and by the way, in order to reach higher energies or shorter distances, an increase in the size of the detectors is needed, Could you please tell me why?. For instance Why do we meed a particle...

Homework Statement A lambda hyperon \Lambda^{0} (mass = 1115.7 MeV/c^2) at rest in the lab frame decays into a neutron n (mass = 939.6 MeV/c^2) and a pion \pi^{0}: \Lambda^{0} \rightarrow n + \pi^{0} What are the kinetic energies (in the lab frame) of the neutron and pion after the decay...

Homework Statement A positron has the same mass as an electron but is of opposite sign (9e-31 kg). What is the sum of the energies of the two photons which are produced when the positron and the electron annihilate? Assume the speed of the positron is .93c (c is the speed of light) with an...

Hi. I'm trying to calculate the adsorption energies at all high symmetry sites on an Aluminium (111) surface (consisting of a few atomic layers). The adsorbates are hydrogen atoms. I make sure that one hydrogen atom per primitive surface cell is adsorbed (i.e. one monolayer of hydrogen atoms...

Homework Statement For a particle moving in a potential V(x), what are plausible forms of V(x) that give: (i) entirely continuous, (ii)entirely quantised (iii) both continuous and quantised energies of the particle? Sketch, with justification, the forms of V(x) for each of...

Hi, I'm starting a prac on muon lifetimes and we have been asked to calculate the range of energies suitable for the experiment... Thinking about this, I was a bit stumped as to what we were supposed to be calculating... Is this a limitation of the detection equipment? Or do low energy...

Does anyone know how to construct a Time-independent wave function with given energies and probability on obtaining energies.

Hi everyone... I hope this is the right place to post. Anyway, I am a first year grad student working on molecular dynamics simulations (with very little background in materials, yay) of iron. To start out, I'm just trying to replicate some materials constants with a basic lattice to make...

Homework Statement Use the bond energies (in Table 4.2) to calculate the energy changes associated with each of these reactions. In each case indicate whether the overall reaction is endothermic or exothermic. Be sure to show your calculation work. [b]2. Homework Equations [/b The...

Just joined so I hope I'm in the right place: My Question: I read that in the creation of a water molecules, a pair of hydrogen molecules break apart releasing 4.53 evolts of energy. Why does the hydrogen spectrum show binding energies of -13.6, -3.4 ,-1.511, -.85, -.544 but not 4.53 or...

I have this problem to solve, but I can't seem to find the right formula. It says to use "an expression for energies of a Bohr atom in a weak magnetic field". I've looked in my coursebook but I can't find anything useful. Can anyone help me?

Homework Statement The overall activation energy E is 60 kcal/mol. Reaction steps are: CH3CHO --> .5CH3CO + .5CH3 + .5H2 E1 = 80 kcal/mol CH3CO --> CH3 + CO E2 = ? CH3 + CH3CHO --> CH4 + CH3CO E3 = 10 kcal/mol CH3 + CH3CO --> minor products...

Is it possible in principle to accelerate particles to arbitrarily high energies? Suppose technology is no bar and there is sufficient money to build accelerators. Can we accelerate particles beyond say Planck energy? or is there is some limit? For example from special relativity we know that to...

hi, I'm new on this forum, and I don't know english very well (sorry). maybe you can clarify me about this doubt. an electron in a well with infinite walls has a discrete set of energies, right? but if the length of the well is infinite, what can I say about energy state density? is it uniform...

Homework Statement Homework Equations Given in the question The Attempt at a Solution Using the numbers and equation given in the question, I got a binding energy of Thorium of 1743.64MeV, and a binding energy of Radon (?) of 1720.88MeV I've come across a number of this style...

Given that the average kinetic energy for molecules of an ideal gas is <E>=3/2kT, how can one find the percentage of molecules of the gas that contain energy above this value?

If one reads the current version of the wikipedia entry on Photoelectric_effect we see that historically the postulate E=h f predates the relativistic theory. So it is kind of circular to argue in terms of E=h \nu to justify E=h f. The empirical process first postulated E=h f for the black...

[SOLVED] energies of spin states Homework Statement An electron is in a constant magnetic field with magnitude B_0, aligned in the -z direction. My book says without explanation: "the spin-up state has energy -\mu_B B_0" where \mu_B is the Bohr magneton I looked back in the Spin...

[SOLVED] Energies of a Hydrogen Atom 1. I have a question on the ratio of energies of an electron in a hydrogen atom. It seems quite simple, but yet seem to be struggling...can anyone help? 2. The question is: "calculate the most probable value of the electron-orbit radius, r, and the ratio of...

Hi, Let's consider a plasma of 3 distinct populations : 1 cold proton population of 0.2 density, 1 hot proton population of 0.8 density, and one electron population. I have T_i=T_e and I set the velocity of my cold population to 0. I expected that te energy of my hot proton population to...

Homework Statement A 2-kg block is dropped from a height of 0.4 m onto a spring force whose constant k is 1960 N/m. Find the maximum distance the spring will be compressed. Homework Equations U1+K1=U2+K2 The Attempt at a Solution both the initial and final kinetic energy should be...

I've looked around and not found any good sources on the gamma energies from fast neutron activation. I need to find the characteristic gamma rays for an MCNP project and currently, I'm relying on energies I get from running some simple cases I set up for the element of interest. Does anyone...

1. Jane, whose mass is 49.0 kg, needs to swing across a river filled with man-eating crocodiles in order to rescue Tarzan, whose mass is 80.0 kg. However, she must swing into a constant horizontal wind force F on a vine that is initially at an angle of with the vertical. (See Fig. P5.73.) In the...

Homework Statement Find the ratio of the energies of the K characteristic x rays of carbon to those of Magnesium. Homework Equations The Attempt at a Solution I did it using Bohr's expression of energy...Is there any other method to do it?

Homework Statement Find the kinetic energy of an electron in the lowest allowed energy state of a hydrogen atom. Homework Equations E = \frac{mv^2}{2} = \frac{mq^4}{2(4\pi\epsilon_0)^2n^2\hbar^2} The Attempt at a Solution m = 9.11* 10^(-31) kg q = 1.6 * 10^(-19) C pi = 3.14 n = 1 hbar =...

Homework Statement A 12.0kg microwave oven is pushed 14.0m up the sloping surface of a loading ramp inclined at an angle 37 degrees above the horizontal, by a constant force F with a magnitude of 120N and acting parallel to the ramp. The coefficient of kinetic friction between the oven and the...

For the well shown below (Attachment or Link belew) solve the time independent one dimensional Schrodinger equation for energies less than V0. You may (and should) leave your answer in terms of a single transcendental equation for the allowed wave numbers. \frac{-\hbar^2}{2m} ...

Hi, let be a Hamiltonian so its energies satisfy E(n)=-E(-n) for every n >0 then my question is does this imply certain symmetry of potential ?? i believe that V(x)=-V(-x) so in absolute value positive and negative energies have the same value.

Hi all I was just looking through my notes from my first year of my degree, and I couldn't find a missing bit. I know that Planck's postulate states that the allowed energies of a quantum simple harmonic oscillator are 0, hf, 2hf etc and that by the Schroedinger equation, you get E(n)=(n+1/2)...

Homework Statement Two neutrons A and B are approaching each other along a common straight line. Each has a constant velocity v as measured in the laboratory. Show that the total energy of neutron B as observed in the rest frame of neutron A is given by...

Homework Statement Consider 10 He atoms as a system Thermodynamically, the state of maximum entropy hence the most likely macrostate for the system is 5 He to be excited and 5 in the ground state. But lower energies are more favourable so there should be more probability for the He to be in...

Edit: I believe this might be in the wrong forum, if it is I am sorry I don't know how to delete or move :( Hey guys quick question! I am studying basic radioactivity just for fun and ran into something that my text doesn't elaborate on. Could someone please clarify? The mass of...

Let's suppose we have a Hamiltonian of the form: \bold H =0 then it's obivious that if you want to get its energies you would get E_{n}=0 for every n, this is a non-sense since you must have positive energies (and a ground state) ...then if we "cheat" :rolleyes: and make: \bold H...

If we apply the Bohr-Sommerfeld quantization to GR (semiclassical) \oint_{S} \pi _{ab} dg_{ab}=\hbar (n+1/2) :confused: :confused: In this case if "Energies" (or whatever you call energy since in Quantum GR H=0 for the "Hamiltonian constraint" ) then using Einstein equation we see that...

If we have a 1-dimensional problem so for big n "Energies" can be found in the form: 2 \int_{a}^{b}dx \sqrt (E_{n} - V(x) ) = (n+1/2) \hbar where "a" and "b" are the turning points, then could we writte the equation for energies (where a>c>b using Mean-value theorem for integrals )...

a block is acted on by a spring with a constant k and a weak force of constant magnitude f. the block is pulled distance x0 from equilbrium and released. it oscillates many times and eventually comes to rest.(the block mass is M). 1)show that the decrease of amplitude is the same for each cycle...

I was wondering whether anyone was able to give me a hint on the following problem: Is the average kinetic energy of all particles in a gas hitting the sides of a container less, equal or more than 3/2kT? And if it is not equal how can you calculate the mean kinetic energy? I was...

Well, I'm working on a lab report for my general chemistry class, and we're supposed to answer questions on bond dissociation energies, but we never even discussed that during the lecture. I cannot find any information on it in my textbook, and I am really lost on how to answer these questions...

A simple harmonic oscillator has a total energy of E. (a) Determine the kinetic and potential energies when the displacement is three-fourths the amplitude. (Give your answer in terms of total energy E of the oscillator.) Kinetic energy ______________ x E <----(times E) Potential energy...

Why the energy eigen values for negetive energies are always discrete while that for positive energies are always continuous? Also what is oscillation theorem?

Rotational energies are in microwave region and vibrational are in infrered region, then how can the both be excited symultaneously? To excite vibrations we need infrared radiation then how can rotations be excited which are in microwave region?

hey where r my recent posts on orbital properties and electron energies?

A 100cm^3 box (1X10^-4 m^3) contains helium at a pressure of 2.0 atm and at a temperature of 100C (373K) It is placed in thermal contact with a 200cm^3 (2x10^-4 m^3) box containing argon at a pressure of 4.0atm and a temp. of 400C (673K) a) What is the initial thermal energy of each gas? b)...

Hi. I'm having some trouble trying to grasp a concept. I know that mathmatically Force perpendicular to motion is zero work. I can't seem to grasp this conceptually. First It seems That is an object is moving right and a force acts straight up on it, it will cause the object to move in a...

Let be the Hamiltonian: H=T+V where V(x)=A(x)+iB(x) then my question is if the Hamiltonian will have real energies..if we apply Ehrenfrest,s theorem for B: i\hbar{\frac{d<B>}{dt}}=<[B,H]> then if B is a function of x and x and p do not commute the derivative of <B> can not be zero...

Let,s suppose we have a qunatum system so the energies are the roots of the function f(x)=0..then my question is that we could calculate the roots to obtain E(0),E(1),E(2),...but the problem comes when we have the integral.. \int_0^{\infty}E(n)dn my question is if for this case we could...

How do you calculate the kinetic and potential energies of the Earth at the perihelion and aphelion? Given that the Earth's orbit is nearly circular GMm/R^2 = m(v^2)/R where M = sun's mass, m = Earth's R = orbital radius so v = √(GM/R) The kinetic energy, E, would be E =...

got a homework problem... What is the relationship between first ionization energies and metallic and non-metallic properties? no idea what they are talking about here.

Ok so i have 5 wavelengths of the rotational spectrum of a certain molecule. I need to find the moment of inertia. I have the equation down to I=(Hbar * wavelength)/(hc) Do i just use the shortest wavelength to figure out the moment of intertia? No radius was given.