Pair Definition and 400 Threads

I'm trying to get my head around this scenario: The blocks are at rest, despite the tension forces acting on them. It is obvious that the static friction acting on A from B is 20N to the right for A to remain at rest (the max might be a lot higher). But does this produce an equal and...

I had to clear this up since there were many threads with the wrong analysis of this problem. Lone pair electrons DO have and affect on dipole moments. Lone pair electrons do have an effect on the net dipole moment of a molecule. A dipole moment is the product of the magnitude of the partial...

Homework Statement What are the angles between lone pairs in H2O? I know that the bonds are separated by 109.5°. What about the lone pair angles? I googled everything. I found nothing. I cannot directly assume it is 109.5°... I have a basic knowledge of VSEPR.

Homework Statement Finding the Fourier Transform using Transform Pair and Properties x(t) = 2[u(t+1)- t^{3}e^{6t}u(t)] Homework Equations The Attempt at a Solution For the first problem, I got u(t) \leftrightarrow ∏δ(ω)+\frac{1}{jω} F(at-t_{0}) \leftrightarrow...

I am not able to understand reaction of magnetic force and how it is equal to qvb ?

Homework Statement http://i.minus.com/jxoYt94CAd9LY.png Homework Equations The total number of valence electrons in SOCl2 is 6 + 6 + 7(2) or 26 valence electrons. Dividing by 8, this implies a total of three bonds formed with the central atom (the least electronegative atom, or...

(A) Total no. of integer ordered pairs $(x,y)$ in $x^2-y! = 2001$ (B) Total no. of integer ordered pairs $(x,y)$ in $x^2-y! = 2013$ My Trail :: (A) Given $x^2-y! = 2001 = 3 \times 23 \times 29 \Rightarrow x^2 -y! = \left(3\times 23 \times 29\right)$ means $(x^2-y!)$ must be divisible by...

\begin{align} u_t + u_{xxx} + 6uu_x &= 0\\ L &= \partial_{xx} + u_t\\ M &= -4\partial_{xxx} - 3(2u\partial_x + u_x) \end{align} For the \(L\) operator, should that be \(u\) not \(u_t\)? I ask because I found \begin{align} \partial_{xx}\psi &= (\lambda - u)\psi\\ \partial_t\psi &=...

Homework Statement How much photon energy would be required to produce a proton-antiproton pair? Where could such a high-energy photon come from? Homework Equations E^{2} = (pc)^{2} + (E_{0})^{2} The Attempt at a Solution Since the photon is massless its energy is E_{i}=pc The final...

Hi, For a final drive of a light commercial truck, I have to design a final drive helical gear pair. The expected ratio is 8.2. The centre distance is 134 mm. The input max. torque is 120 Nm. I have sized few combinations. I have a feeling that this ratio is too deep. Pl. share me your...

Hi all, I'm not so expert in C++, but I try to make a a simple program to calculate and plot the ttbar pair mass invariant distributtion by pythia in pp collition (pp -> ttbar), taking the events from .lhe file in pythia exampls. Now about the program attached here , i made the steps...

WHat is the permissible maximum transmission ratio of a Spur gear pair? I read somewhere that it is 1:5. What wil happen if this is exceeded?

I am trying to understand the pairing mechanism in the Cooper pair in real space. When I googled the image of the Cooper pair, there are two different pictures explaining the pairing. While one describe the second electron moving in the same direction, other describe it as moving along the same...

hi, i just need a quick clarification on pair production. from my limited understanding, a photon of sufficiently high energy (gramma ray with energy at least equal to the mass of both an electron and positron at rest) will interact with a nucleus in ways that i do not understand to...

We have ## ||a+b|-|a|-|b|| ##. The only way I can think to eliminate one pair of absolute value signs is to consider the cases separately and determine which pair(s) can be removed without affecting the final answer. I'm trying to get better at doing these types of problems, so feel free to...

Homework Statement A 2000kg car pushes a 1000kg garbage can at constant speed . The car exerts a force of magnitude CB on the garbage can, and the garbage can exerts a force BC on the car. Which force has greater magnitude, or are they equal? explain Homework Equations Fcb=-Fbc The...

This is actually related to a post I made earlier in the differential equations forums, but I've since realized that solving the equations themselves is not necessarily the best way to get where I want to go. Perhaps it's better suited to this forum, since it is an integration problem that I...

I'm having a bit of trouble understanding why a nucleus is needed for a gamma ray to interact with in particle pair production. I know that all properties are conserved - spin, charge, etc. -, and I know that the photon must have at least the energy of twice the standing energy of the particle...

Hi everyone, new member zeroseven here. First, I want to say that it's great to have a forum like this! Looking forward to participating in the discussion. Anyway, I need to solve a pair of differential equations for an initial value problem, but am not sure if an analytical solution exists. I...

Hi all, Let's say you are at rest with respect to the galaxy, and you have low energy photons all around you. Now, if I crank my energies up relatvisitcally, the frequency and thus E = hf of those photons will increase. Red Light becomes Blue Light, Blue Light becomes UV, UV to X-ray, and...

Homework Statement I have math experiment where I roll a pair of honest dice 20 times. The results are: 2,3,4,4,5,5,6,6,6,7,7,7,7,7,9,9,9,10,10,11 write a frequency table of the outcome of the dice roll with respect to size: 2,3,4,5,6,7,8,9,10,11,12 Firstly there must 36...

Show that one of the bisectors of the angles between the pair of straight lines ax2+2hxy+by2=0 will pass through the point of intersection of the straight lines ax2+2hxy+by2+2gx+2fy+c=0 if h(g2-f2)=fg(a-b) Please help

If each of the equations ax^2+2hxy+by^2+2gx+2fy+c=0 and ax^2+2hxy+by^2-2gx-2fy+c=0 represents a pair of straight lines , find the area of the parallelogram enclosed by them . Please help

Hi there. Just a few quick questions: What causes a photon to become an antimatter / matter pair? Is it just random? Can a photon be influenced to encourage it to change? Also what is the process called? Do we say the photon has decayed? That doesn't seem right to me. In addition, if...

There are certain key pairs of RSA that will return the same exact value when encrypt and decrypt, for example (5,7) and (13,19) is there a mathematical pattern that describes this behavior? Any advice would be appreciated

Hello, I have a doubt about the high frequency response of the MOSFET (or BJT as well) differential couple in the case it's polarized by a current mirror. Here's a picture of my issue (it shows the semi-differential circuit of a MOSFET differential couple with a "small" common mode ac input...

Homework Statement Find a pair of functions f(x), g(x) such that the following are true lim x->3+ f(x) = +∞ lim x->3+ g(x) = +∞ lim x->3+ (f(x)-g(x)) ≠0 Homework Equations none The Attempt at a Solution f(x) = x/x-3 g(x) 3/x-3 ?

what are pair production and pair annihilation phenomena?

Allover the web i am only seeing a statement similar to this: "Pair production is not possible in vaccum, 3rd particle is needed so that conservation of momentum holds." Well no one out of many writers shows, how to prove this matematically. So this is what interests me here. First i wanted...

I am wondering in which theory pair productioon is described? Is it field theory, particle physics or quantum physics? I am sorry for such a basic question, but i need this info to find some books which will explain pair production mathematically and not by waving hands... (like allover the web)...

According to Newton 3rd law, every action will have a reaction. but how about buoyant force? if the buoyant force is the force of water on object then the reaction force will be the force of object on water. but is it other name for this force? thanks for reply.

Hi, I'm quite new to quantum mechanics, learning about it in my free time in a life-long learning fashion :) I've been trying to find a solution to a problem for some time, and the results I included below appear to be OK, but I have doubts about the method I used, so any help or guidance...

I know that if a photon has enough energy, it can split off into a particle and anti-particle. But how does that happen exactly? Does the photon just randomly decides to split off? With annihilation (opposite of pair production), the process is much easier to visualize for me, because you...

So this headset has stereo sound and a mic, but the connector only has a tip ring and sleeve. So which part of the connector is for each. (tip for left channel, ring for right channel, sleeve for common, so where does the mic connect.)

Homework Statement Ok I know Fourier transform pair for u(t) is pi*del(w)+1/(j*w) Am I right to say the transform pair of u(t)-u(t-1) is [pi*del(w)+1/(j*w)]-[pi*del(w-1)+1/(j*(w-1)] If not what is it? thanks

Hi, I was thinking of possibly majoring in astrophysics, but I cannot think of any good minor to accompany an astrophysics major. Does anyone know of a good minor that would supplement a major in astrophysics and be of some use?

Homework Statement How long would an electron-positron pair exist for in "the vacuum" [of space]? To create an electron-positron pair requires at least 2mc^2 = 1.6 x 10^-13 J Homework Equations ΔEΔt ~ (h-bar)/2 The Attempt at a Solution Δt ~ (h-bar)/2ΔE Δt ~ (1.05 x 10^-34) /...

Homework Statement A and B alternate rolling a pair of dice, stopping either when A rolls the sum 9 or when B rolls the sum 6. Assuming that A rolls first, find the probability that the final roll is made by A. The Attempt at a Solution A rolls a sum 9 on each roll with prob 1/9 B rolls a...

A pair of perpendicular vectors... √Homework Statement This thread contains 2 questions that are similar. A pair of 482.5 N vectors are perpendicular. What is the magnitude of their resultant? Answer in units of N Two vectors of magnitudes 24 N and 31.1 N act at right angles to each other...

Im New on this forum, so i hope this is the right place to ask this question. I've tried to solve the problem of finding how many hands are in a poker game with exactly one pair, this way: I can choose the first card from 52 ways. for the second card I can choose it from 3 ways (to match the...

Suppose you have two lines that intersect at the point O. Let's say the lines are OP and OQ. Could you construct a plane that contains both these lines? I can visually imagine this happening in the 3-space, but I may be wrong. I was just wondering, because this allows one to define an angle...

Does the cooper pairs spins (up and down) cancelling out have anything to do with anything? Is the current spin polarized in a superconductor?

Hello to everyone! What are the feynman diagramms for the three basic photon interactions? Photelectric Compton(compton, Rayleigh and Thomsom scattering) Pair Production Thank you in advance!

Here is an example in which the normal force would not be counted as an action-reaction pair. A 100g block is sitting at rest on a horizontal table. According to Newton's third law, which of the following indicates the correct action-reaction pair of the two forces? So I was stuck between C. The...

Homework Statement You will calculate the change in the magnitude of momentum between each pair of adjacent locations. Begin by calculating ∆ |~pBC|,the change between locations B and C ~pB = 2.03, 2.83, 0 kg · m/s ~pC =1.55, 0.97, 0 kg · m/s ~pD = 2.24, −0.57, 0 kg · m/s ~pE = 7.97...

Please explain the logic, as this is the definition provided by the book I am referring to.

Hi all. I have a (probably stupid) question about e^{+}e^{-} annihilation. I was reading about the emission of two 511keV photons which is the electron's mass. But, is this energy fixed every time e^{+}e^{-} annihilates in a two photons or is just the energy of the positronium dacay? My idea...

I just started studying set theory, and I've seen this definition for an ordered pair (a,b) = {{a}, {a,b}} However, I don't understand how this definition makes sense. Could someone explain this definition to me? Maybe use a concrete example too?

Calculate the energy is takes to create a positron-electron pair and place the electron in the lowest energy state of a nucleus of charge 푍푒 and the positron infinitely far away. Show that for a sufficiently high charge the creation of the electron-positron pair gives a net release of energy and...

Pair production interests me - create matter from electromagnetic waves. So far I have read that a Positron-Electron pair can be created by photons having energy exceeding twice the rest energy (m * c ^ 2) of an electron (1.022 MeV). So, if you have photons exceeding the energy of an up...