Weak Definition and 503 Threads

Homework Statement What particle(s) does the weak force affect? I think it's electrons but my teacher thought it was quarks since the range of the weak force is <0.003 fm.

Homework Statement We have two solutions: One solution that has 0.300 L of 0.100 M acetic acid, and the other with 0.100 L of 0.200 M CN^-. We mix the two solutions. At equilibrium, what is the pH of the resulting solution? Homework Equations For acetic acid, K_a=1.8*10^{-5} For CN^-...

I understand that there is an issue about the FF-dual term in the strong sector. But I believe I can write an analogous term in the SU(2) part of the electroweak sector. Why don't people worry quite as much about this term (the Weak analog of the 'Strong CP Problem')?

Hello, Im trying to find out if, since an electron positron pair can anhillate to produce a muon-anti muon pair by the weak interaction, can the same thing occur for the production of an electron/anti-electron pair? Or would it just happen by the electromagnetic force? Or both, with the weak...

I did an acid/base titration with acetic acid and sodium hydroxide to determine the concentration of acetic acid present in vinegar but I'm not quite sure how to go about calculating the concentration of it. First things first we dissolved 25ml of vinegar into 250ml of water and filled the...

Homework Statement 800ml sample of 2.00 molar formic acid HCOOH (or HA) ismixed with 200ml of a 4.80 molar NaOH. Calculate the [H3O+] of the resulting solution. Homework Equations (for buffers) pH=pKa-log(HA/A-) Ka for formic acid is 1.8x10-4 pH=14-pOH [H+]=(1.00x10-14)/([OH-) The...

I've heard the weak force described as essentially "a force between particles with flavor" just as the EM is "a force between particles with charge". Mathematically, I understand the concept of the CKM matrix being used to evaluate the weak force eigenstates of quarks, but I'm confused as to how...

Using the Schrodinger equation for an electron in a periodic potential where U(r +R) [R is the translation vector R=n1a1+n2a2+n3a3 and ni are intergers and ai are teh primitive lattice vectors, G is for reciprocal lattice G=n1b1+n2b2+n3b3 and ni are intergers and bi= (2PI*aj x ak)/(a1 . a2 x...

Homework Statement How do i get the Ka of weak base indicators such as bromophenol blue, methly red, bromothymol blue, and phenolophalein? I found the pKa values online but i couldn't find their Ka values.

(purpose is to find molar mass) At the start we dissolved 0.945 grams of unknown weak acid into water and made it up to 100 ml Then we used 25 ml of that solution and titrated it until the end point. Now , this is a monoprotic acid so it's going to take 1 mol of acid to neutralise 1 mol of...

Hi all, When working on some GTR derivations the authors of the text make approximations based on the magnitude of the gravitational field. What are the general limits of strong and weak gravitational fields?

Hi... Consider a neutrino with a Dirac mass m_\nu and the weak interaction {\cal{L}}=\frac{g}{2 \sqrt{2}} \sum_l[{W_{\mu}^+ \cdot \bar{\psi}_{\nu_l} \gamma^{\mu}(1-\gamma_5)\psi_l + W_{\mu}^- \cdot \bar{\psi}_{l} \gamma^{\mu}(1-\gamma_5)\psi_{\nu_l} }\right{]} + \frac{g}{4...

Hi, Dirichlet's theorem states that any arithmetic progression a+kb, where k is a natural number and a and b are relatively prime, contains infinite number of primes. I'm wondering if there is an easy proof of a much weaker statement: every arithmetic progression a+kb where gcd(a,b)=1...

weak "force" this is really just a question about terminology, so I am not expecting any overly complex answers. I am familiar with the weak interaction, but in what sense is this a force? It is unlike anything that we would consider a force.. The only sense in which I can see it being...

Hi: The electromagnetic and weak interactions were unified in what is called the electroweak interaction, but as long as I know they are different classes of interactions, what I mean is that in weak interactions, there are particles that transform in others (like neutron's beta...

Hey, I'm going into my senior year of high school and am applying to some prestigious engineering schools namely berkeley =/ and am concerned about my senior year schedule. it is as follows: IB English II IB Spanish 6 IB European History II IB Physics II TOK/ ? (Maybe law or some history...

Hi All I have a question that I require an answer to. For the above titration, concentration of A-(conjugate base of acid) is the same as concentration of HA at half equivalence. It is at this point that pka=ph of the solution. I agree to this conclusion, but why is the concentration of A-...

Why is it called the 'weak force'? what makes it weak?

the question is simply to determine the [OH-] and pH of a solution that is .210 M in HCO3- first of all if i can get [OH-] then i can easily get pH by converting [OH-] to [H+] and then doing the -log[H+] so that part is easy. i just cannot get [OH-] what i did was first write the...

One can predict by which mechanism a reaction will occur, Sn2 or Sn1, by the substrate's order( i.e. primary, secondary, or tertiary carbon) and by the strength of the nucleophile. How can I tell if a nucleophile is strong or weak? For instance, one problem showed methanol combining with...

Hi, After actually struggling to find anything relevant in books/google/this forum I'd really appreciate if someone could enlighten me: W^{\mu\nu} What is meant by this exactly? Can I write this down in matrix form like the EM tensor? Thanks Ben

I could benefit from someone shedding some light on a couple of questions that I have regarding the speed of various entites: 1) It seems that the speed of gravity, e.g, if the sun disappeared, is the speed of light WRT things I've read. What is it that would inherently cause gravity to travel...

Is weak interaction invaraint under CPT Symmetry? Why?

I attach a solution to a problem. I don't understand the highlighted bit: I mean, firstly why can we assume that qc (where q is the momentum transfer) is of the order of the hyperons rest mass energy? And secondly, why is the rest mass energy of the W boson MORE than the rest mass energy of...

Hi, just curious because I don't have it in my notes, say for fixed A (Atomic Number) we have Z_s which is the proton number that gives max stability. For Z =/= Z_s there are 3 1st order weak process that occur, does anyone know what these are? And when Z is far from Z_s there are two strong...

I have just read, in general, weak interactions, have the lowest Q values; meaning they have the smallest cross sections, which means they control processes in stars at some time in the early universe. What would be the next relative strength? Cheers

Homework Statement What observation of the process: (anti muon neutrino) + (electron) -> (anti muon neutrino) + (electron) constitutes unambiguous evidence for weak neutral currents, whereas the observation of (anti electron neutrino) + (electron) -> (anti electron neutrino) +...

I am baffled by what exactly it means to have the following (ingoing, outgoing) lepton pair configuration: (0,\nu_L e_R^+) and (e_L^- \bar{\nu}_R,0) This specific question was asked in Halzen and Martin exercise 12.3. How is it possible to have 0 in going particles and a neutrino and electron...

Procedure: 1. Pipette 25 cm3 of ethanoic acid into a conical flask 2. Titrate against 0.1M sodium hydroxide solution in the burrette, using phenolphthalein as indicator. 3. Pipette further 25 cm3 of ethanoic acid into the solution after titration and mix throughly. Questions: 1. what is...

Homework Statement I'm working on the last section of the last chapter (11.9 The Higgs Mechanism) of Griffith's book on Elementary Particles. In Problem 11.25 I'm asked to derive the lagrangian that he gets juts after gauging [Eq. 11.131]. That's the one with a Goldstone boson and a strange...

Homework Statement Titrating .1006M CH3COOH with .2012M NaOH. pKa=4.74, Ka=1.8*10^-5 What is the pH at the equivalence point of the titration? Homework Equations pKa = -log(Ka) pH = -log[H+] The Attempt at a Solution Alright, after setting up an ICE table (in order to find...

http://postbiota.org/pipermail/tt/2007-May/000515.html Does anyone know what happened with these experiments?

Hi I was studying the WLLN and the CLT. A form of WLLN states that if X_{n} is a sequence of random variables, it satisfies WLLN if there exist sequences a_{n} and b_{n} such that b_{n} is positive and increasing to infinity such that \frac{S_{n}-a_{n}}{b_{n}} \rightarrow 0 [convergence in...

Homework Statement For the weak field metric g_{00}=-1+\epsilon h_{00}+O(\epsilon^2) g_{\alpha\beta}=\delta_{\alpha\beta}+\epsilon h_{\alpha\beta}+O(\epsilon^2) Prove R_{00}=-\frac{1}{2}\epsilon\frac{\partial^2h_{00}}{\partial x^\alpha\partial x^\beta}+O(\epsilon^2) Homework Equations The hint...

I encountered an argument that says that the weak mediators must be massive because the weak force is short range, by the uncertainty principle. But isn't the uncertainty principle relates the uncertainty in mass, \delta m and \delta t and not the absolute value of the mass?

Homework Statement A hydrogen atom, which is in its ground state 1s (i.e. \|1,0,0\rangle), is put into a weak time-dependent external electric field, which points into the z direction: \boldsymbol{E}(t,\boldsymbol{r}) = \frac{C\hat{\text{\boldsymbol{e}}}_{z}}{t^{2}+\tau^{2}}, where C and...

strong and weak electrolytes-need help pleasez hi all i need help to solve the following exercise Given: those are a strong electrolyt limiting , and we give the molar conductivity for each ion in ( S.Cm2/mol) HCl 426.1 CH3COONA 91.05 HF 405 NaCl 126.5 1- why did thos electrolyts has...

strong and weak electrolytes-need help pleasez hi all i need help to solve the following exercise Given: strong electrolyt limiting molar conductivity of ion i ( S.Cm2/mol) HCl 426.1 CH3COONA 91.05...

Homework Statement We did a lab in class about weak acid/strong base titration, but I'm having a bit of trouble. We we only given the molarities of an unknown weak acid and a strong base (NaOH) and the pH of six different mixtures containing different mL of the two, which is below: Test...

Homework Statement Show that if {x_k} is any sequence of points in space R^n with |{x_k}| \rightarrow \infty , then \delta(x-x_k) \rightarrow 0 weakly Homework Equations The Attempt at a Solution I'm still trying to grasp the concept of weak convergence for distributions. It...

Hi, i just need to get together all the conservations/violations that the weak interaction conserves/violates. I know about parity, charge conjugation and basic properties such as charge and lepton number but i was wandering if anybody could think of any more. No mathematics please! Thanks.

Homework Statement I had a whole list of reactions and had to show whether or not they could occur... I understood most of the reasons, bar the following, but was more confused about whether or not a reaction was strong or weak... I know that if the reaction involves a lepton its weak, and if...

Hi I have been trying several days to solve this problem. But i can't find the procedure to solve this weak acid and weak base problem. I will really appreciate some help. What is the pH of a soft drink in which the major buffer ingredients are 6.90 g of NaH2PO4 and 5.70 g of Na2HPO4 per...

Hi I have been trying several days to solve this problem. But i can't find the procedure to solve this weak acid and weak base problem. I will really appreciate some help. What is the pH of a soft drink in which the major buffer ingredients are 6.90 g of NaH2PO4 and 5.70 g of Na2HPO4 per...

25 mL of 0.1 M HOAc are titrated with 0.15 M NaOH. What is the pH at equivalence? I know that the pH at start will be greater than 1.0 and the pH at equivalence will be greater than 7 since its a titration of a weak acid and a strong base. But what I don't know is whether or not there is a...

Can someone explain to me briefly what is weak localiztion and anti-localization and its effect on magnetotransport? Thank you.

Take the sequence x_n = (1-1/n)e_n in l^2 Consider the map l^2 to R given by x |--> ||x||^2 The set A = {x_n} in l ^2 is closed & its image is not closed in R under the norm topology (it doesn't contain its accumulation point 1). So ultimately the above map is not closed. What I'm...

Hey guys, I don't know what I should do. I mean I love biology...but its just that I have tried those methods which are suppose to make memorization easier for you but it still is pretty hard(relating the word to your senses or memory). What do you guys think?

gravity and weak force is it possible to compare the strength of weak force to gravity and if so how is weak force stronger than gravity?

I came upon a very interesting article today: http://www.msnbc.msn.com/id/19875410/site/newsweek/ I wanted to confirm what I read... this is the first time I ever heard of this kind of thing, and I was wondering if any of you have seen this before. It talks about a tweak of Young's...