Principle Definition and 1000 Threads

Homework Statement Use the following trial function: \Psi=e^{-(\alpha)r} to estimate the ground state energy of the central potential: V(r)=(\frac{1}{2})m(\omega^{2})r^{2} The Attempt at a Solution Normalizing the trial wave function (separating the radial and spherical part)...

Homework Statement I know how to prove that square root of 2 is irrational using the well ordering principle but what I'm wondering is, how can we use the well ordering principle to prove this when the square root of two isn't even a subset of the natural numbers? Doesn't the well ordering...

Homework Statement I have to solve this question in two ways, the first is from kinetics and kinematics and the second from the principle of work and energy. For the the first problem I obtained 3.160643122 for the acceleration at b(pulley with force t) and proceeded to find to find the...

Hello! I have a doubt about Heisenberg uncertainty principle. Suppose that a particle moves along x-axis with a given uncertainty in velocity. Can I say something about its motion along y-axis? Thanks

I have read the basis of the the equivalence principle, that inertial mass = gravitational mass, and that it leads to the conclusion that any acceleration = equivalent gravitational field intensity. (I believe 'gravitational field intensity' is the same as 'gravitational acceleration'.)...

Here is a question, that is so many levels above my analytical, logical, mathematical and physics skills (which sum up, in my case, to no more than popular science and science fiction reading), so the only reason that i am still asking this question, is that, not asking a question, seems to me...

Hey everyone, I've been trying to figure out what went wrong here for abit now and I think maybe a fresh pair of eyes might help. If anyone could point me in the direction of my error that would be great. Thanks Homework Statement An effective treatment for some cancerous tumors is...

Okay, so Pascal's Principle (as copied from Wikipedia): A change in pressure at any point in an enclosed fluid at rest is transmitted undiminished to all points in the fluid. From what I've gathered, this means that pressure in liquids act in all directions, so if you press a closed...

Homework Statement The problem and its solution are attached as TheProblemAndSolution.jpg. Homework Equations Δx = λ/sinθ Δp_x = 2h/λ sinθ The Attempt at a Solution In the equation given in the problem (Δx = λ/sinθ), why is the uncertainty of the ELECTRON written as a function of the...

existence of protons, neutrons nd alpha particles in the nucleus.

I'm sending this message to anyone who has knowledge about neutron generator. is there anyone who knows how does penning ion source works. I mean how could ions exit the holes but electrons can't exit. I didn't find any explanation about it on the web

I've been reading extensively around the internet and haven't been able to find a website which describes the philosophical implications of Heisenberg's uncertainty principle. Would appreciate if someone would explain these implications or provide a link in which describes them. thx

Homework Statement I was looking at a solution inmy notes which begins: ΔE = hc/λ -1st eqn ΔEΔt ~ (h-bar)/E -2nd eqn Δt ~ (h-bar)/ (hc/λ) Δt ~ λ/2∏c (where 'c' is the speed of light) What formula has been used to go from: Δt ~ (h-bar)/ (hc/λ) to Δt ~ λ/2∏c...

If I have a body (for simplicity a cube with side d) on a fluid (with density ρ) with its top at a depth h, the force acting on top of it is ma = (h*d*d)*ρ*(g); where g is the acceleration of gravity, (d*d*h) is the volume of the column of liquid on top of the cube and that times ρ is the mass...

In statistical mechanics, nearly all the textbooks say that the volume of the smallest cell in the phase space of a N-particle system is h^{rN} where h is the Planck Constant, r is the degree of freedom. Also these books say that this comes from the uncertainty principle. However, the...

Can someone please explain the history of Heisenberg discovered his uncertainty principle? Was he trying to physically measure the position and momentum of an electron to disprove the old atom model or did he just do it hypothetically?

I was just wondering if our use of a flat Minkowski background metric when looking at gravitational radiation in the weak-field limit is essentially done so that locally, for example with detectors on Earth, we can treat spacetime as being flat, but on a larger scale we use the equivalence...

Homework Statement The input and output pistons of a hydraulic jack are respectively 1 cm and 4 cm in diameter. A lever with a mechanical advantage of 6 is used to apply force to the input piston. How much mass can the jack lift if a force of 180 N is applied to the lever and efficiency is...

Hello, I was taking a shower and started to think about balloons and helium and this question came to me: Wouldn't the things on Earth be lighter than say, a similar planet (same gravity) but with no atmosphere? (because of the push from air) I googled it but I am not sure of using the correct...

This might be interpreted by some to border on the fringes on pseudo-science, but I feel logic dictates that conclusion must be one of many possibilities according to the theories. Has anyone ever considered that the many worlds interpretation combined with the anthropic principle has some...

To quote cosmologist Ned Wright: If the Universe is the same at all times, it is argued that the value of the Hubble parameter must be a constant H_0, so H = \frac{\dot{a}}{a} = H_0 leading to an exponential cosmology a(t) = e^{H_0 (t - t_0)} where t_0 is the present age of the Universe...

Homework Statement Assume that a particle travels with a certain known (average) velocity ##v = \left\langle\hat{p}/m\right\rangle##. You know it's position with an uncertainty ##Δx##. Use the uncertainty principle to determine the least possible value for the article's kinetic energy...

Probably, the essence of quantum theory (QT) is principle of uncertainty (HUP). The essence of QT is also the fact that Fourier transformation of wave function in phase(?) space gives wave function in momentum space. If one wave function is Gaussian (and so both ones) this gives HUP. Very...

Homework Statement Please click on the following link for the solution. http://s1292.photobucket.com/albums/b580/cathy12121/?action=view&current=Bernoullisequation_zps0d4485d7.jpg Homework Equations P1 + .5(rho)v12 + (rho)gy1 = P2 + .5(rho)v22 + (rho)gy2 The Attempt at a...

some books mention one of a basis of GR is mach principle i study some text but i can't actually realize it please explain it for me or introduce some books to refer them thanks

Ground State Wave Equation: ψ0=(a/∏)(1/4)e(-ax2/2) Prove the Heisenberg Uncertainty principle ≥h(bar)/2 by way of expectation values. First I found <x>=0 because it was an odd function then I found <Px>=0 because it was an odd function Then <x2>=∫(a/∏)(1/2)x2e(-ax2)/2dx=1/2a by way of...

I have used the attached photo to show that light takes the path described by snells law such that the time it takes from point A to B is minimized. But conceptually there is something wrong for me in this derivation. Because why would the light ray coming in, know that there is a different...

Can someone explain to me how a gyroscope works non-mathematically?

hello.. I am reading "Relativity, the Special and The General theory of relativity by A. Einstein", and i have a few doubts that i wish to clarify. In one of the section there are two arguments given in favor of the principle of Relativity,one being that laws of classical mechanics apply...

A girl and her sledge have a combined mass of 40kg. She starts from rest and descends a slope which is inclined at 25 degrees to the horizontal. At the bottom of the slope the ground becomes horizontal for 15m before rising at 6 degrees to the horizontal. The girl travels 25m up the slope before...

Homework Statement The speed of an electron is measured to within an uncertainty of 2e4 m/s. What is the size of the smallest region of space in which the electron can be confined? Homework Equations Diracs Constant=ΔxΔp p=mv The Attempt at a Solution what I did was (Diracs...

I have had similar questions posted, but I am not quite sure on this one and it seems that my textbooks have trouble agreeing completely aswell. As far as I understand it: Hamiltons principle: δI = δ∫Ldt = 0 is only satisfied for systems, where the generalized forces can be put in a...

I appreciate that the holographic principle is just a theory, but if I accept it and the related aspects of string theory, does it do away with the need for dark matter (since I think that the mass approaches infinity as one changes the reference frame in which one observes the the mass)...

Homework Statement (Squeeze Principle) Suppose f, g, and h are real-valued functions on a neighborhood of a (perhaps not including the point a itself). Suppose f(x) ≤ g(x) ≤ h(x) for all x and limx→a f(x) = l = limx→a h(x). Prove that limx→a g(x) = l. (Hint: Given ε > 0, show that there is δ...

Hello I would appreciate if someone can refresh my mind with the principle of superposition..

Homework Statement You are navigating a spacecraft in space. The mass of the spacecraft is 4.0 x 10^4 kg. The engines are off, and you're coasting with a constant velocity of ‹ 0, 28, 0 › km/s. As you pass the location ‹ 5, 6, 0 › km you briefly fire side thruster rockets, so that your...

Equivalence Principle: A hint on how to start! Hi, I have no idea where to start. 1. Statement Problem Let X be a non empty set with a equivalence relation ~ on it. Prove that for all x,y\inX, [x]=[y] if and only if x~y. Homework Equations For the Equivalence Relation to exist, it...

Pascal's principle hydraulic lift with torque involved(need help with lever) Homework Statement A hydraulic jack is used to support a mass which has a mass of 30.7 kg. The mass is supported by piston 2 which has a mass of 0.250 kg and an area of 40.2 cm2 . A force is applied by the lever on...

How sound do you think the following research is? http://phys.org/news/2012-09-scientists-renowned-uncertainty-principle.html

So the integral of the lagrangian over time must be stationary according to hamiltons principle. One can show that this leads to the euler lagrange equations, one for each pair of coordinates (qi,qi'). But my book has now started on defining a generalized lagrangian where lagrangian...

Are fictitious forces and constraint forces the same thing?

I have some trouble understanding how my book introduces the variational formulation of mechanics. On the attached file I have stipulated with red a part, which I do not understand at all. What is the idea behind introducing this differential quantity: δJ = dJ/dα * dα and writing the...

Ok, so this problem looks like an induction problem to me, so I used that, but I only got as far as the induction hypothesis. The hint says to use the pigeon hole principle. I'm not sure how to use that for this problem.

Neumann's Principle states: If a crystal is invariant with respect to certain symmetry elements, any of its physical properties must also be invariant with respect to the same symmetry elements. So, does this apply to the wavefunction of an electron in a crystal? Or, stated another way, if...

Should relativity be factored into the uncertainty principle. I can't move faster than c so should that affect the measurement process? Should time dilation and length contraction be considered or maybe some of these factors cancel when 2 effects are considered.

The D'Alembert's Principle states that: \sum_s [\underline{ F_s^{applied}} - \frac{d}{dt} (\underline{p_s}) ] \cdot \underline{δr_s} = 0 s - labels particles That is when F_s doesn't include the constraint forces, and the virtual displacement is reversible, and compatible with the...

Homework Statement Let F: N->N be defined by f(1)=1 and f(2)=2 and f(n+2)=1/2(f(n+1)+f(n)) Use Theorem 1.3 to prove that 1<=f(n)<=2 for all n in N Homework Equations For each n in N let P(n) be a statement about the positive integer n. If a) P(1) is true, and b) for k>1, P(k) is...

Hi, I'm a non-expert on LQG, and have a question about it: What is the status of the correspondence principle applied to LQG? I.e., in which sense can we take the classical (h --> 0) or non-relativistic (c --> oo) limit in order to obtain classical GR or Newtonian gravity out of LQG...

http://chutzpah.typepad.com/.a/6a00e55180ed5c88340120a75cf644970b-pi How do the circles still intersect at the bottom, and at 2 points like the top 2 circles?

hello! which is the principle and technology that enables us to measure objectively myopia, astigmatism and presbyopia? thanks!