Principle Definition and 1000 Threads

Homework Statement Hello guys my name is Mathias I'm 15 years and i have been tasked to show a little experiment in my school class. It's concerning Heisenbergs principle, you have probably all heard about this demonstration. It's basically firing a laser beam through a narrow passage...

"The Beer-Lambert relationship must be solved using a FeSCN2+ standard solution. This standard solution can be prepared by mixing a SCN- solution that has a very low concentration with a Fe3+ solution that has avery high concentration. In this situation, the reaction is driven to completion...

Homework Statement a) A car of mass 1050kg moves along a straight horizontal road with its engine working at a constant rate of 25kW. Its speed at a point A on the road is 12ms-1. Assuming that there is no resistance to motion, calculate the time taken for the car to travel from A until it...

The 3s and 3p orbitals are filled by 4 electrons.A single atom has [Ne]3s2 3p2.But when multiple atoms get together they do so in order to minimize the overall energy.And to minimize the overall energy,the 3s and 3p orbitals hybridize to form 4 tetrahedral SP3 orbitals.And the Si atoms get...

Hi Guys, Newbie question from a layperson so please don't beat me up! :D I know that Heisenberg's Uncertainty Principle relates to measurement/observation of particles with regard to quantum physics. My question is whether or not it applies to measuring anything in the observable...

Homework Statement Using the Uncertainty Principle show arithmetically that neutrons can't be formed by a proton and an electron. Homework Equations The Attempt at a Solution I can see that if neutrons were made out of a proton and an electron they would just attract each until...

Homework Statement Explain, using the Heisenberg Uncertainty Principle, how classical physics is reached a a limit of quantum physics when (h-bar) tends to 0. Homework Equations ΔxΔp(x) ≥ (h-bar)/2 The Attempt at a Solution The only reasonable answer I can formulate is the fact that when...

Homework Statement Show using Boltzmann's principle (S=k.lnW), show that with respect to changes in V and T: dS=k.N.\frac{dV}V{}+\frac{C.dT}V{T} Where W=T^{\frac{C}k{}}V^{N}The Attempt at a Solution S=k.lnT^{\frac{C}k{}}V^{N}=k.lnT^{\frac{C}k{}}+klnV^{N} S=C.lnT+N.lnV Now I know that the...

According to the uncertainty principle Δp*Δx≥h/2pi, now suppose we measure a particle in a very tiny area(if x is tiny enough), s.t. Δp ≥ h/(2xpi) ≥ mc then v > c. But in fact, the velocity can not be faster than light. So how can we compromise these two statement?

Homework Statement A hot air balloon with V = 500 m^3 is floating in the air without moving. The air outside the balloon has a density of 1,20 kg/m^3, and the hot air inside the balloon has a density of 0,75 kg/m^3. Calculate the total mass of the hot air balloon. Homework Equations...

1. For the past 1 hour, I'm trying to derive lens maker's equation using fermat's principle, which of course is our homework. Any help would be great regarding the topic. 2. According to Fermat's Principle, optical path length OPL = PA + AQ, here PA and AQ are two rays. Now using this I...

Homework Statement Assume that V = 4.8V and I = 3.2mA. Find Ix in the figure using the principle of superposition. Homework Equations V=IR Kirchhoff's Current Law Kirchhoff's Voltage Law Total response = ∑responses from each individual source The Attempt at a Solution I believe I'm...

Hi all! So rumor has it, that the spin of a particle is preferably aligned opposite to the direction of the particle's momentum, whereas an antiparticle spins along the direction of motion. For the sake of simplicity let us assume that the (anti-)particle is massless and hence it is an...

This could be one of those questions where I'm hindered by my lack of knowledge on the subject, being only a freshman in college, but recently we learned the uncertainty principle which states that: ΔE*Δt ≥ h/4π Given this, I'm assuming it'd be accurate to rewrite ΔE as Δm*c2, which would...

The uncertainty in this principle is talking about uncertainty of measurement or particle itself?

Homework Statement I have to find voltage at point 2 using superposition method. So, I drew one circuit with no voltage source and another with no current source, and then tried to analyze each one separately. (On the picture starting from left, its 10 volts, then 10ohms, then at top 5...

Homework Statement Laser can now be designed to emit pulses of light smaller than 30 microns wide in their direction of motion. (a) Estimate the uncertainty in the momentum of a photon in such a pulse. (b) The momentum of a photon is p=h/λ. Estimate the uncertainty in the...

if you know the position why can't you know the momentum isnt p=mv and v=dx/dt its the only doubt i have so far please help

Hi, I know this is old news at this stage, but I was watching his public lecture on quantum mechanics, and he says the energy levels of all the electrons in the universe shift to adjust when he adds energy to electrons in a diamond. I understand that he should have used the phrase quantum...

Homework Statement Does Bohr's correspondence principle apply only to quantum theory? Can you give an example of the applications of this principle to relativity theory? Homework Equations The Attempt at a Solution According to my textbook, Bohr's Correspondence Principle simply...

Homework Statement I'm interested in an explanation of the forces/principles involved in the following scenario: There are two syringes, level with one another, containing the same volume of water. The difference between the syringes is the gauge of the needle; one is of greater diameter...

Confuses me. In which case is it the helmholtz free energy, the gibbs free energy, the energy that gets minimized and why? Also is it consistent with energy conservation and how is that possible if you use it on two systems exchanging energy. Can we know the total energy of the total system for...

Homework Statement A photon near the surface of the Earth travels a horizontal distance of 3 km. How far (in meters) does the photon 'fall' in this time? (Hint: think equivalence principle). Homework Equations N/A The Attempt at a Solution My understanding of the equivalence...

Hi all - I was having a debate with some students in my flipped class today and I can't wrap my head around Bernoulli's Principle as it relates to the sea. Can anyone explain how Bernoulli's principle works with a sail boat? I don't know how the force vectors resolve to push a sail boat...

For those who read carefully the paper by Esther Hänggi and Stephanie Wehner: "A violation of the uncertainty principle implies a violation of the second law of thermodynamics": 1. Can you elaborate how extra work can be extracted if the UP is violated? 2. Does the paper implies that...

I don't know what is the principle of Fizeau's method. In the experiment a rotating toothed wheel is used.But why the toothed wheel is used? If the toothed wheel is not used,why the time for the light traveled cannot be measured?

Homework Statement A masspoint finds itself under the influence of gravity and constrained to move on a (inverted) circular cone. Using D'Alembert's Principle find the equations of motion on cylindric coordinates. Homework Equations D'Alembert's Principle: (\vec{F_a}...

Homework Statement Derive from the uncertainty principle a formula for the relative spread of the spectral line that corresponds to the longest wavelength of the Lyman series. Homework Equations uncertainty principle: σxσp≥\hbar/2 planck constant \hbar=h/2pi h=λp Lyman series...

I've been asked to research D'Alembert's principle and solve a question. I've looked up quite a lot of different explanations on the internet of D'Alembert's Principle and I'm not quite grasping how to use it. I understand that you rearrange formula so that they equal 0 (e.g. f - ma = 0 or PE -...

Let's assume as per the anthropic principle, for the mere sake of argument alone, that the physical constants of the universe are indeed biased towards life and that any significant change would eradicate the possibility of any form of conscious life. For the sake of argument as well, let's...

Hi! How this paper relates to the equivalence principle? http://arxiv.org/pdf/gr-qc/0701084.pdf "in contrast to the situation with static gravitational forces, the effects of accelerative gee-forces on the internal observer are increased"

I don't know much about physics but just had this idea: As I understand it the HUP prevents good accuracy of a small object's momentum and position at the same time. Assume trying to measure the momentum and position of a single atom. In theory, can't we get a very good idea of both of...

This has botherd me for quite sometime ...imagine a beam or a simple scale supported at its centre and carrying equal weights on two extreme positions on the scale from the centre, now under equilibrium the scale will be horizontal...now my question is if one of the weight is lowered by action...

Hi I am reading Stephan Hawking's Universe in the Nutshell and there I didnt understand this sentence "This equivalence didn't work for a spherical Earth because people on opposite sides of the world would be getting farther away from each other.Einstein overcome this idea to make spacetime...

In principle does classical physics allow us to make a fair N-sided die where N ≥ 3? If I give you a set of N positive numbers n_i whose sum is 1 can a N-sided die be made in principle such that each face of the N-sided die comes up on average with a probability n_i? Can N above be reduced to...

I have a specific problem involving two reservoirs filled with water with a height difference Y and total head H, and was wondering if a venturi like device could be used to calculate the resulting pressure head x and if it will exceed the bottom of reservoir 1. Also the drain length is d...

I understand that accepting Hamilton's principle will yield identical results as accepting Newton's laws. However, simply accepting that the integral of the difference between kinetic and potential energies is an extrema seems not intuitively obvious. The textbook that I used for my classical...

I know I have seen this before a few time done a few different ways/starting points and I am always blown away when I see it worked out. Don't know why but I love seeing this derivation. Does anyone want to post the derivation for all to see, it being done a few different ways would be great.

My source is the high school chemistry textbook: General Chemistry, 2nd Edition, by Donald A. McQuarrie and Peter A. Rock, published 1987 (This is not for a high school homework assignment.) According to Heisenberg's Uncertainty Principle, the product of the uncertainty in the momentum...

Hi. New member to this Physics forum and not a physicist, although have an interest in physics from a layman's position. I saw a series of threads on a Twitter discussion posted about a year ago concerning Brian Cox and some other physicists concerning a statement made by Cox that the...

Homework Statement We have a chinese lantern (balloon) made of paper, cylinder shaped with the following sizes: base diameter - 45 cm, height - 70 cm. Mass of the balloon is 57 g (21 g from this is mass of "fuel" - the fuel is wax paper!). Fuel is then ignited at the centre of the base, which...

Homework Statement So here's the question An electron is confined within a region of width 1 X 10^-10 meters. Estimate the uncertainty in the x component of the electrons momentum Homework Equations ΔPΔx\geq(1/2)(h/2pi) The Attempt at a Solution The problem appears pretty...

I am studying some simple models of how conduction arises on a microscopic level. A central idea is the following: Look at two leads attached by a conducting channel. Initially the system as a whole is in equilibrium which especially means that the chemical potential μ is the same everywhere...

Hello, Recently I've learned about Fourier Transform, and the uncertainty principle that is arose from it. According to Fourier Transform, if there is only one pulse in a signal, then it is composed from a lot more frequencies, compared to the number of frequencies that are building a...

Homework Statement A block of wood floats in fresh water with 0.722 of its volume V submerged and in oil with 0.895 V submerged. Find the density of (a) the wood and (b) the oil. Homework Equations mass = density x volume f = ma conservation of mass F_{weight} - F_{buoyancy} =...

Homework Statement A particle of mass m is in a potential of V(x) = Kx4 and the wave function is given as ψ(x)= e^-(ax2) use the variational principle to estimate the ground state energy. Part B: The true ground state energy wave function for this potential is a symmetric function of x...

Hello there, I am struggling in proving the following. The principle of Minimum energy for an elastic body (no body forces, no applied tractions) says that the equilibrium state minimizes $$\int_{\Omega} \nabla^{(s)} u D (\nabla^{(s)}u)$$ among all vectorial functions u satisfying the...

Hi everyone, :) Here's a question with the summary of my method of how to solve it. I would really appreciate if you could go through it and let me know if there are any mistakes with my approach. Also are there any easier methods? Problem: Find an orthogonal transformation that reduces the...

I just got to the chapter of Quantum Physics in this book for amateurs. A couple of questions: If Planck's constant was smaller than it actually is, then how the uncertainty principle be affected? What if Planck's constant was zero? ALSO: When you flip a coin, the outcome is uncertain. Does...

Hi, I tried to google it, but I got much more confused with different and contradictory definitions. Can somebody please help me understand the difference between these terms? Is there overlapping between them? Some books say "Law of conservation of energy", but others say "Principle of...