Properties Definition and 1000 Threads

Title basically says it all. I'm a physics undergrad trying to wrap my head around quantum physics, and I was hoping people here could help. My question comes from something in one of my textbooks. It tries to explain particle-wave duality through a piece of string, which I'll quickly go over as...

Homework Statement Light with wavelengths of 520 nm and 630 nm passes through a diffraction grating that contains 6000lines/cm. a) Sketch a diagram of the image produced from m = 0 to m = 2. Label the order of each fringe. b) Calculate the angles for the first and second order maxima that would...

Hi, just curious: I saw a result that for the multiplicative group G:= {1,-1, i, -i } , "every homomorphism ## h: G \rightarrow G ## is of the form ## z \rightarrow z^k ## for some ##k \in \mathbb Z ##. I can show this is true by considering the image of a generator, but I was wondering if...

Hi all - in the question below I could do with some help on the "..explanation for the relative strengths..." bit, as I can't think of anything to say. 1. Homework Statement Compare and contrast the properties of the strong and weak interactions. Include in your account an explanation for the...

I am doing some self study of groups and can solve problem #3 but not Problem #4. Problem 3. Let A be a finite set, and B a subset of A. Let G be the subset of S_A consisting of all of the permutations f of A such that f(x) is in B for every x in B. Prove that G is a subgroup of S_A. Problem...

I'd trouble remembering decision properties of languages like Regular, CFL, RE, etc. So I made a table of it. Are all the entries of table correct or has some errors http://postimg.org/image/bdb5tqkfl/][/PLAIN] http://s24.postimg.org/bdb5tqkfl/Decision_Property.jpg

Hello! (Wave) For each pair of natural numbers $m \in \omega, n \in \omega$ we define the multiplication between $m,n$ (as a function $\cdot: \omega \times \omega \to \omega $) like that: $$m \cdot 0=0$$ $$m \cdot n'=m \cdot n+m$$ I want to show that for each $m \in \omega, n \in \omega, k...

Hello! (Wave) For each pair of natural numbers $m \in \omega, n \in \omega$ we define: $$m+0=m\\m+n'=(m+n)'$$ We fix a $m$ and recursively the operation $m+n$ is defined for any $n \in \omega$. Knowing for example that $m+0=m$ we can conclude what $m+1$ means. $$m+1=m+0'=(m+0)'=m'$$ and...

I had a couple of questions. 1. Why does the integral ∫exf(t) dt transform to ex∫f(t) dt? Shouldn't ex be a part of the integrand too? 2. Why is the difference dy - dy1 = d(y - y1)?

Hi all, I have a few questions regarding electron shells and seeing if they should be intuitively connected to de Broglie's description of electrons as waves. I teach high school level and occasionally get wild questions...if I can ever help a student in the slightest I am inclined to try. So...

Homework Statement Dear Mentors/PF helpers, Please help me with part (ii), I couldn't find a way through this part. Homework Equations The Attempt at a Solution My solutions: (i) angle RPS = 65 deg (angles in the same segment are equal) (iii) angle PRS = 110 - 65 = 45 ( exterior...

Hi all, I have a general question about material properties. We know that the material property value depends on the input level. For example, the permittivity in a dielectric material changes depending on the applied electric field. That being said, when we apply an alternating electric...

O is the centre of the circle and XTY is a tangent to the circle. The chord TC intersects the diameter BOD at Z. If angle TÂB = 124° and angle CBD = 28° calculate 1) angle YTB 2) angle CTD 3) angle BOT 4)angle DZC 5) angle OTD 6) angle CTY

What would be the reducing reaction for these in water?

Homework Statement If the shear stress in steel exceeds about 4.0 x 10^8 N/m^2, the steel ruptures. Determine the shear force necessary to punch a 1-cm diameter hole in a steel plate that is 0.5 cm thick. Homework Equations The Attempt at a Solution The way I tried to solve this problem...

What I'm asking for is if there is a guide for the properties of processes like isochoric, isobaric, isothermal and adiabatic. For instance, a comprehensive guide that tells me that the pressure in an isobaric expansion is the same before and after, etc. If there isn't, does anybody have any...

Homework Statement I have problem with properties of compatible observable Homework Equations [AB,CD]=AB CD – CD AB ………. (1) ABCD+ACBD-ACBD-ACDB+ACDB+CADB-CADB-CDAB ………. (2) A{C,B}D-AC{D,B}+{C,A}DB-C{D,A}B ... (3) The Attempt at a Solution How can the equation (1) become (2), and eq (2)...

Homework Statement Let ##O## be a proper open subset of ##\mathbb{R}^d## (i.e.## O## is open, nonempty, and is not equal to ##\mathbb{R}^d##). For each ##n\in \mathbb{N}## let ##O_n=\big\{x\in O : d(x,O^c)>1/n\big\}## Prove that: (a) ##O_n## is open and ##O_n\subset O## for all ##n\in...

Hello! (Nerd) I want to write an algorithm that checks if a binary tree has the properties of a $\text{ 2-3 tree }$. The properties of the $\text{ 2-3 trees }$ are the following : All the leaves have the same depth and hold one or two elements. Each internal node: either holds one...

Hi! (Wave) We have an $\text{AVL tree}$ and we are given a key $r$. I want to write an algorithm that finds the depth and height of the node, of which the key is $r$. So, do we have to compare the key of the root with the key $r$ and if it is greater we will have to continue at the left...

Are there any particles on the Standard Model of Particle Physics with all the properties of a WIMP particle(Weakly Interacting Massive Particles)?

I was wondering, how does a photon look like? What does it look like? I'm taking modern physics at the moment and I'm able to calculate lots of things quite well. Like DeBroglie wavelengths, I'm able to utilize the Schrodinger equation and the Heisenberg uncertainty principle and what not but I...

Say a person was descending at constant rate of 1m/s while holding a ball. Then, without stopping, the person dropped the ball which assumed a free fall. Would the ball assume an initial velocity of 0m/s, or would it start at the one 1m/s that the person is traveling? If anyone can, please...

Hi All, Please let me set things up before the actual question: I have a Lefschetz fibration ## f: W^4 \rightarrow S^2 ## , where ## W^4## is a closed, oriented manifold, and ## S^2## is the 2-disk. This f is a smooth map with finitely-many singularities {## x_1, x_2,..,x_n ##}, so that we have...

How exactly does light move through space in terms of EM radiation and photons. What I'm confused about is the electromagnetic field. How does it oscillate, and in which directions? Also do photons have Electromagnetic fields associated with them?

If you had to a create a super element to be added to the periodic table, what would it be? I'm talking about it's properties.. give me some good techno babble.

hi guys I am trying to understand the properties of waves, does a wave oscillate on a 2 dimensional or 3 dimensional plane? if a wave need a hole the size of its double its amplitude to pass through un-effected can it pass though a thin slot with a length that is double the waves amplitude...

Hi. I'm looking for a recommendation for a book (or website) that has detailed information on properties of materials. Specifically on mechanical properties. A book that covers all grades of materials, not just a general guide. I'm forever to-ing and fro-ing between websites, datasheets and my...

Hi All, AFAIK, the key property that separates/differentiates a Hilbert Space H from your generic normed inner-product vector space is that , in H, the norm is generated by an inner-product, i.e., for every vector ##v##, we have## ||v||_H= <v,v>_H^{1/2} ##, and a generalized version of the...

How did he figure out the many properties of the Universe such as time dilation/relativity and energy matter equivalence and his numerous other contributions. This might be a dumb question but was this all just done on paper? I don't recall reading that Einstein ever conducted experiments...

Hi all, I'm wondering if anyone knows of a way to obtain elasticity properties (Ex, Ey, Ez, Gxy, Gxz, Gyz, vxy, vxz, vyz) from the terms of a 6x6 anisotropic stiffness or compliance matrix. I'm looking for a closed form solution, preferably. I would think that there should be a closed form...

I just studied about the QM of singlet spin pairs. I have additional questions. Neither Wikipedia, nor past threads on this forum seem to address the questions. 1) A pair of electrons forming a singlet pair A. Can the pair be split again into non-entangled electrons? If yes how; just hit...

Does anyone know of a class or a textbook or anywhere to start doing research on how to start off with a set of desired properties of a material and begin designing that material from a molecular level. A for instance would be say you want a material that is capable to separating oxygen from...

Hi, I need help with some basic Fourier transform properties stuff - its fairly simple though I think I am doing something wrong. So we know from the shifting property if h(x) has the Fourier transform H(f) then h(x-a) has the Fourier transform H(f)ei*2*π*f*a so I have the function cos(2πf0x...

Homework Statement Prove the following property: If m <= f(x,y) <= M \hspace{2 mm} \forall (x,y) \in D, then: mA(D) <= \int\int f(x,y)\,dA <= MA(D) Homework Equations I use a few other known properties in the proof (see below) The Attempt at a Solution First, I should state that this problem...

Hey Folks, I wanted to put together a single spreadsheet of subatomic particles (e-, ν, b, t, π Ξ, Σ, Δ, etc.) and their properties that have been measured (mass, mean lifetime, valence quark content, charge, spin, parity, etc.). I have been looking through the PDG website for some way to...

Homework Statement This problem is very easy, but I'm not sure how best to "prove" it. This part of the question just states: Prove that (1/z)* = 1/(z*) where z* is the complex conjugate of z. Homework Equations The Attempt at a Solution So the complex conjugate of z = x + iy is defined is...

It is often stated and proved in textbooks that the momentum density is also the energy flux. The explanation is often done using the dust model. However, it is possible that in a real fluid, there is heat conduction via particle collision. There is energy flux, but since no molecules are ever...

Homework Statement Let ##f,g## be non-negative Lebesgue measurable functions, and let ##E## be a measurable set. Prove that: ##f\ge g\implies \int_E f d\lambda \le \int_E g d\lambda## Homework EquationsThe Attempt at a Solution I've been trying to apply Fatou's lemma but haven't been getting...

Homework Statement Determine which of the formulas hold for all invertible nhttp://msr02.math.mcgill.ca/webwork2_files/jsMath/fonts/cmsy10/alpha/144/char02.png n matrices A andB A. 7A is invertible B. ABA^−1=B C. A+B is invertible D. (A+B)2=A2+B2+2AB E. (A+A^−1)^8=A8+A−8 F...

Dear all, In one of his lectures,Prof. Susskind mentioned that the event horizon "bulges" forward to meet any incoming radiation or matter; and it is a property of Einstein field equations. I have not come across any such property, and if it exists, shouldn't it belong to the Schwarzschild(or...

Hey everybody; There is something I don't understand. I need to find the properties(E,Poisson's ratio, G) of e-glass fiber 420 gm bi-bias. I find some interesting websites but each time when they give properties, they don't give the basis weight. So if I understand, mechanical properties are...

Hi, let ##h: A \rightarrow A ##be a homomorphism between algebraic structures. Is there a nice result describing the properties of ##Ker h^2 ## , where ##h^2 = hoh ## (composition) ? Clearly , ## ker( h) \subset ker (h^2 )## , but are there some other results relating the two; maybe relating...

Homework Statement from -lnIxI to lnI x^-1I , I try to go from -lnIxI to lnI x^-1I by using some properties. Homework Equations - lnIxI The Attempt at a Solution First I write the -lnIxI as -1*lnIxI and then I use -1 as an exponent to absolute value of x in the natural log that is ln (...

Hi I need help regarding following can I write following partial derivative wrt x multiplied by Ax (∂A[x])Ax =∂(Ax^2)

Hi there I need to know the density, viscosity, heat capacity,and temperature for the oil or crud oil? Also I need to know the wall temperature for pipe? Can anyone help me please ?

How can you tell NH3 is a better base than HOCOO-? I look at the conjugate species in both to determine their relative stabilities. Where NH4+ is the conjugate acid of ammonia and HOCOOH the conjugate acid for acetate. In this case, isn't the NH3 more stable than NH4+ since it is uncharged yet...

When looking at the cage or structure used to carry materials into an oven for the annealing process, what material properties are most important? Lets saying during full annealing of aluminum, the oven is heated to 540 degrees Celsius. A cage is used to carry the aluminum into the oven...

x + 0 = x x - 0 = x x(0) = 0 x(0) = undefined ...is this how you call it or is it no solution? x^0 = ? What is x raised to the zero power? square root of 0 = ? Not sure about this one either. If anyone knows of any other properties of zero I'm leaving out, please feel free to...

If there is a graph that has a discontinuity (e.g. at x = 3) and then the there is a point much lower than the limit at 3, is that point at 3 considered a local minimum? Also, if the graph starts w/ a discontinuity at its "highest point", does it have an absolute maximum?