What is Pair: Definition and 399 Discussions

An au pair (; plural: au pairs) is a helper from a foreign country working for, and living as part of, a host family. Typically, au pairs take on a share of the family's responsibility for childcare, and receive a monetary allowance for personal use. Au pair arrangements are often subject to government restrictions which specify an age range usually from 18 - 26 years of age, both male (BroPair) and female AuPairs are avaliable. The au pair program is considered a form of cultural exchange that gives the family and the au pairs a chance to experience and learn new cultures.
Arrangements differ between Europe, where the concept originated, and North America. In Europe, au pairs are only supposed to work part-time, and they often also study part-time, generally focusing on the language of the host country. In the United States, they may provide full-time childcare. In 1969, the European Agreement on Au Pair Placement was signed, and it came into force in 1971. Au pair companies in the United States have significant non-refundable fees once the au pair arrives in the country. The contract does not guarantee childcare, despite many families' reliance on the program.
Unlike many other types of domestic assistants, the au pair is considered a part of the host family and not merely an employee. In some countries the au pair wears a uniform, but more commonly the au pair only follows the host family's dress code and wears attire appropriate for the work description, typically including a protective apron.

View More On Wikipedia.org
  1. E

    Probability problem -- Number of throws of a pair of dice to get a 7

    Homework Statement The minimum number of throws of a pair of dice so that the probability of getting the sum of the digits on the dice equal to 7 on atleast one throw is greater than 0.95, is n. Find n. Homework EquationsThe Attempt at a Solution There are 6 possible ways of getting a sum of...
  2. Ryan Reed

    Are there Quark-Antiquark Particles?

    There are exotic atoms such as the protonium (proton+antiproton) and positronium (electron+positron); I was wondering if quark-antiquark particles could appear even if they only exist for a fraction of a second.
  3. C

    Hybridized AOs: Where is the lone pair?

    can unhybridized atomic orbitals hold sigma bond electron pairs? To my knowledge, hybridized AOs can hold both lone pair e- as well as sigma bond e- pairs. But I'm not sure if unhybridized AOs can do the same. Thanks in advance!:smile::wink:
  4. S

    Electron-positron pair production

    Is it true that static electric field 10^16 V/cm2 is capable to create positron-electron pairs? Is this process associated with energy release? If yes, where energy comes from?
  5. S

    Hi-Q resonator and photon pair

    I am trying to "perform" a thought experiment suggested in http://arxiv.org/ftp/quant-ph/papers/0206/0206190.pdf (Not that I personally have anything against non-locality :angel: Some of my best friends are non-local.) A source generates a single, narrow gated pulse of light containing one...
  6. T

    Accelerating protons and antiprotons for pair production?

    Okay so I have a problem with what my textbook is saying. It defined pair production as a process in which a photon of electromagnetic energy is converted to a pair of particles. But then it gave the discovery of an antiproton. Which was when a proton was accelerated to 6MeV and collided into...
  7. S

    Finding energy from dipole moment - Helmholtz pair?

    Firstly apologies for not typing this out - but I need the diagram. And I have no idea where to start. I 'think' most of it is correct. BUT - I have no idea what to do with the last part of c. I thought I could just double the energy. But I'm going to get a negative energy for the system...
  8. S

    Finding resultant at each pair of forces

    Find the resultant of each pair of forces acting on an object Q: forces of 6 N southwest and 8 N northwest I got 10 for the resultant, but how do I find the angle? The answer is apparently is 10 N, N82degW Having a hard time visualizing this...
  9. U

    Why don't a charm-anticharm meson decay to pair of leptons?

    If you consider the ##\chi_0 ## with a mass of ## 3.4 GeV/c^2## meson, why doesn't it decay to a pair of charged leptons? Technically it is possible though the weak interaction (Z boson) or EM interaction, right? Is it because it is so heavily suppressed because the strong interactions are...
  10. R

    Combinatorics: Complementary Pair

    Homework Statement My book repeatedly uses the phrase "contains one of each complementary pair of sets" and I am wondering what do they mean by that exactly? Homework Equations None The Attempt at a Solution For example, when it proves that an intersecting family of subsets of...
  11. K

    What do you mean by Cooper pair in real space and k space?

    So i came to know that electrons residing across a tiny shell around fermi momentum takes part into the game of forming cooper pair but this phenomenon in real space is actually different. here all the electrons are taking part into this. what does it mean. i am not able to comprehend this...
  12. ShayanJ

    How a pair spectrometer works?

    I need to know how a pair spectrometer works but I can't find a book that explains it in detail. They say that it has three crystals located in a line and the beam is collimated on the central crystal and somehow this signal is only analyzed when there are simultaneous signals from the other two...
  13. ShayanJ

    Pair production differential cross section

    In one of my classes, I should give a talk about pair production cross section in front of the class and so I'm now searching for resources. But I can't find a place where the differential cross section for pair production process is given. Anyone knows somewhere I can find it and , preferably...
  14. A

    Why Mesons Can't Be Made of 2 Quarks Alone

    As far as I know a Baryon is made of three Quarks (eg uud, udd etc) and a Meson of two Quarks, a Quark/Antiquark pair. As I am not a student / scholar in Physics but very deeply interested in this field, I couldn't find any explanation, why a Meson is omly made up by a Quark/Antiquark pair. What...
  15. M

    The Cooper pair box Hamiltonian in the matrix form

    Hello, In my problem I need to We are advised to create the Cooper pair box Hamiltonian in a matrix form in the charge basis for charge states from 0 to 5. Here is the Hamiltonian we are given H=E_C(n-n_g)^2 \left|n\right\rangle\left\langle...
  16. BubblesAreUs

    Finding Lower Bounds for {2, 4} using Partial Order

    Since I'm not sure if posting assignment questions is allowed, I'm just going to ask specific questions just to be safe. 1. Homework Statement Find all the lower bounds of given pair. Say (a, b) in T. Homework Equations Proof for greatest lower bound: ∀g,a,b ∈ T ⇔ ( g ≺ a) ^ (g ≺ b) ^ (...
  17. A

    Pair production inside the atom?

    Why there is no electron-positron production inside the, let say, Hydrogen atom?. I know that the electric field near nucleus get modified by some form factors making it not as big as the Coulomb field, but still i think is still very big.
  18. Feeble Wonk

    Graviton represented as a gluon pair

    I'm not a physicist, but I'm pathologically curious about such things. I've recently heard that there is a growing school of thought among theoretical physicists that the graviton (and resultant gravitational force) is actually just an extension of the strong force conveyed by a gluon pair. This...
  19. Prof. 27

    Understanding Nested Ordered Pairs: Properties & Examples

    Homework Statement One way of modeling tuples in set theory is through nested ordered pairs. A notation I'm not familiar with (I'm assuming it means that the following elements are nested into the last one) is used. (a1, a2, a2,... an) = (a1(a2, a3,..., an)). I have never seen the second "(" in...
  20. arpon

    What is the minimum energy required to produce an electron-positron pair?

    Homework Statement The antiparticle of electron is positron, whose mass is the same as electrons, i.e. 9.1 * 10^{-31} kg but the charge is opposite. What is the minimum energy required to produce a electron-positron pair? 2. Homework Equations E = mc^2 The Attempt at a Solution Actually I...
  21. P

    Snake instability and vortex pair

    Dark soliton is a general phynomenon in broad physics subjects. In higher dimensions, dark soliton exhibits instable except one special kind as vortex. The fundamental instability of a single dark soliton in two dimensions is to eventually decay into a number of quantized vortics through what is...
  22. I

    Quantum entanglement: where is the pair?

    I am trying to read some of the experiments on entanglement. Is the pair of photons or electrons created by a laser hitting crystal? If this is so, then a pair of particles emerges? If this is also so, what is the big deal where the measurement occurs? The particles are created together at...
  23. anorlunda

    Can Singlet Spin Pairs Behave Like Bosons?

    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...
  24. evinda

    MHB Exploring: Relation & Ordered Pair

    Hey! (Cool) According to my notes, each relation is a subset of an ordered pair. How can it be that each relation is a subset of an ordered pair, knowing that a relation is a set of ordered pairs? (Thinking)
  25. M

    On partitioning an even number into a pair of (relative) primes

    An example:For m= 176 (132<176<172 one finds r=(3-2)x(5-2)x(7-2)x(11-1)x(13-2)=1650 relative primes (0<v<2x3x5x7x11x13), forming 825 asymmetric pairs, among them four partitions into prime numbers:19+157, 37+139, 67+109, 73+103, 79+97.
  26. DiracPool

    Is Love Real or Just an Artifact?

    Nice to hear your comments...
  27. K

    Stumped on a box on cart action/reaction pair question

    Homework Statement Consider a box sitting on cart. When the cart is pulled with a force, P, the box A moves with the cart without slipping. In all questions, assume there is a negligible amount of drag. There is, however, kinetic friction between the cart and ground. What are the two sets of...
  28. M

    LED/IR Pair for Leaky Faucet Experiment

    Hello Friends, I'm building a version of the leaky faucet experiment. Which is to say, I'm going to measure the period of water dripping out of a valve. To measure the event of the droplet falling I want to use an LED/IR pair. My understanding is that these things are basically like super...
  29. avito009

    Exploring Pair Production: Helium Nuclei in Matter Creation

    Does pair production use helium nuclei for matter creation? Pair production occurs when a photon (Light Particle) strikes a heavy nucleus, it disintegrates and produces a pair of an electron and a positron. Is that heavy nucleus of Helium?
  30. C

    Newton's third Law - action reaction pair

    Hi, I am a little confused with the concept of action reaction pair of forces. Does this depend on mass? For example, if a train engine is pulling a buggy with force F, what would be the force applied by the buggy on the engine? The masses of the two are different and there is force of...
  31. B

    Pair production question - photon to electron/positron

    Homework Statement http://puu.sh/brbpb/3c7573fa32.png Homework Equations E = (mc^2 +K + mc^2 + K) P = E/c E = mc^2 The Attempt at a Solution The book says that the momentum/kinetic energy of the electron and positron produced in a pair production is so small that it can be...
  32. N

    An electric dipole consists of a pair of equal but opposite charges

    Homework Statement An electric dipole consists of a pair of equal but opposite charges, +Q and -Q separated by a distance d. What is the electric potential at the point that's midway between these source charges? Through using the formula electric potential = kQ/r, I found the electric...
  33. T

    Pair Production by two photons : energy range of the electron created

    Hi all, I'm currently studying pair production by two photons (a high-energy one traveling in a isotropic field of low-energy ones), and I'm trying to understand the energy range of the electron created by this phenomenon. For this, I'm studying an old paper from Aharonian 1983...
  34. V

    Cross section in muon pair production from electron positron annihilat

    I have a question regarding the calculation of the cross section in muon pair production from electron positron annihilation. After some calculations the textbook comes to the conclusion that the differential cross section is approximately equal to: (1+cos(theta)^2)alpha^2/(4*s) where alpha...
  35. J

    Can any pair of spacelike events be simultaneous?

    I was looking at some space-time diagrams with the simultaneity surfaces for moving inertial observers in SR and looking at the picture an interesting thought came up to my mind. It is known that the causal structure of the universe is preserved in SR, and that cause always comes before the...
  36. xortdsc

    Escape velocity of electron/positron pair

    Hi, is there a way to compute the escape velocity/kinetic energy of a newly created electron/positron pair ? Or in other words: How much excess energy (beyond 2 times electron mass) has to be put into the creation such that they will escape each other into infinity ? Thanks and cheers
  37. C

    Understanding Additive Pair Potential in Molecular Dynamics

    I'm sorry, I wasn't exactly sure where to put this question but this section is probably my best bet. I'm basically trying to understand potential functions of more than 1 parameter... which is basically, most potential functions out there for molecular dynamics, what I just started working...
  38. marellasunny

    Why do I need a processing code when I pair Arduino with bluetooth

    Why do I need a "processing" code when I pair Arduino with bluetooth I have a need to connect my [Arduino+Bluetooth dongle JY-MCU V1.02] to my laptop in-built bluetooth device.Most forums suggest using a processing code to go ahead and do this...
  39. mishima

    What makes a good Darlington pair (as sensor)?

    I wanted to try using a Darlington pair with an ion chamber (small tube) to detect alpha particles, as this site explains: http://www.techlib.com/science/ion.html Before I order any components, I was wanting to throw something together with some normal transistors I already have. I was...
  40. P

    Determining Spring Constant in Ion Pair

    Homework Statement The force between an ion pair is given by F=-k\alpha\frac{e^{2}}{r^{2}}[1-\left(\frac{r_{\circ}}{r}\right)^{m-1}] Find the value of r where the equilibrium position is. Determine the effective spring constant for small oscillations from the equilibrium. Using...
  41. C

    Pair Production, electron and positron from isolated photon

    I don't completely understand why an electron positron pair cannot be created from an isolated photon. I understand it must have something to do with 4 momentum conservation, but I really can't see a problem given the photon has enough energy for the mass to energy vice versa conversion.\ The...
  42. A

    Rationalization of bond angle/ bond pair repulsions.

    Homework Statement I need help rationalizing the following: a) Bond angle for H2S is only 92o whereas bond angle for H2O is 104.5o. b) If bond-pair<-> bond-pair repulsion is maximum for the C-H bonds in CH3X, ∑ all bond angles is 450o for CH3X c) For CH2Br2, the H-C-Br will be the smallest...
  43. S

    Feynman diagram for pair annihilation

    Hi, I've been reading about Feynman diagrams lately and I'm trying to understand the pair annihilation diagram. The picture's here: http://en.wikipedia.org/wiki/File:Feynman_EP_Annihilation.svg I don't understand the following things about the diagram: 1. Why anti-patricles have to...
  44. R

    Can a SINGLE photon produce an electron-positron pair?

    A homework question is asking for a diagram illustrating a photon becoming a electron-positron pair (please don't post an image as it's homework). Looking through the internet there seems to be some disagreement as to whether a single photon can create an electron-positron pair: "Show that...
  45. xortdsc

    Is positronium really an orbiting pair of electron/positron ?

    Hi, I'm a little confused about positronium. Accouring to this article http://www.answers.com/topic/positronium it states on the one hand that it is just an electron and a positron orbiting around their common center, held together by electro-magnetic forces due to their charge. On the...
  46. D

    Annihilation of electron positron pair

    Suppose in thought experiment one electron positron pair is annihilated in the carriage of fast moving train while the other pair is annihilated on the platform . Will the frequency of the photon reaching the platform from the carriage will be same as given out by the other pair which which is...
  47. M

    How does the production of a top quark pair occur in a proton-proton collision?

    Hi there, My homework problem is on particle physics and asks me to draw a feynman diagram for pp→\bar{t} t interaction, which is what I think the LHC is planning to do (or possibly is doing). For the more traditional interaction; \bar{p} p→\bar{t} t I have this diagram; In this...
  48. B

    Final value theorems to each transform pair

    Homework Statement Find f(t) for the function F(s)=(10s^2+85s+95)/(s^2+6s+5) and apply the initial and final value theorems to each transform pairHomework Equations Initial value theorem: f(0)=lim s->∞ s(F(s)) Final value theorem: f(∞) = lim s->0 s(F(s))The Attempt at a Solution After dividing...
  49. P

    DTFT question regarding a pair

    Homework Statement My book writes the following: using pair for the Discrete Time Fourier Transform: -a^{k}u[-k-1] <---(DTFT)---> \frac{1}{1-ae^{-iw}} for \left | a \right | > 1 Homework Equations Well, for the simple similar pair such as: a^{k}u[k] <---(DTFT)--->...
  50. J

    Static friction between two stacked blocks a 3rd law pair?

    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...
Back
Top