Rules Definition and 539 Threads

Homework Statement (a) Determine the currents I1, I2, I3 in the figure. Assume the internal resistance of each batter is r = 1.0 olms (b) What is the terminal voltage of the 6.0 V battery? I hope you can read my handwriting. Homework Equations V = IR The Attempt at a...

Homework Statement Using Kirchhoff's rules, find the currents I1, I2, and I3 in the circuit shown where R1 = 8.0 ohms, R2 = 9.0 ohms, and R3 = 5.0 ohms. Homework Equations Loop law, Junction lawThe Attempt at a Solution I know how to work the formulas, but the picture is really confusing. The...

I'm trying to work out the correct algorithm for using Kirchoff's rules when using a non-ohmic resistor like a light bulb. The problem is that the resistance depends on the voltage, but the voltage may depend on the resistance (a simple example: a bulb and a resistor in series: how should the...

I'm learning QFT by reading Lewis Ryder's book, so my question in short is: how he arrives at Eq 7.57 and Eq 7.58? If you don't have the book, the question is: why are there Minkowski metric terms in the Feynman rules for a gauge field coupling to itself? If the answer is complicated, simply...

boolean equation = A̅D + AB̅C̅D = D (A̅ + AB̅C̅) * rule A + A̅B = AB ? = A̅D + B̅C̅D am i using the rule correct or does A̅ + A make it a 1 and answer D(1)

I'm not sure if this is the right place to post a graduate level course material, but I have a question about perturbative expansion of the 2n-point function of a scalar field theory. Homework Statement First, the question: In which space (position or momentum) is the topological distinctness...

The Born rule says that if a system is prepared in state |a>, and a measurement of an observable Q is performed, the probability that the result is qi is P(q_i)=|\langle q_i|a\rangle|^2 The ABL rule (Aharonov, Bergmann, Lebowitz) says that if a system is prepared in state |a>, and a...

Homework Statement In an ABC toy theory, the only allowed vertex is one that couples A, B and C. Thus there are no AAA, ABB, ACC...ect vertices allowed. My question is suppose a diagram has na external A lines, nb external B lines, and nc external C lines. Develop a simple criterion for...

This is so wrong, IMO. http://news.yahoo.com/s/ap/20081120/ap_ca/bush_endangered_species

A standard definition of energy is the ability to do work. Work is defined as the movement of matter through the application of force (measured in Newtons). Yet in the Standard Model of particle physics, various bosons represent "energy particles" that are the intermediaries for each of the...

Does anyone have a straightforward link to linearity rules? My textbook is not very helpful and my prof never knows what he is talking about :(. I have a few "prove this is not linear" questions to do f(x)=(|x1|,|x2|) f(x)=(1,2)+3x f(x)=(0,1) I should know this, but i tend to forget the...

What changes to the algebraic rules when imaginary "i" is introduced in addition to real numbers? I know that complex numbers do not have a "<" or ">" relation. Some functions become multivalued. What about school algebra? Maybe exponentiation rules are slightly modified?

Homework Statement What is the IUPAC name for the following compound. (Benzene with two chlorines sticking out one at Carbon 2 the other at Carbon 5) Homework Equations The Attempt at a Solution I understand that the compound's name has to be something like 2,5-dichlorobenzene but...

Hi. I know that for real numbers log(z)=-log(1/z) is this also true in general for complex numbers?

Homework Statement a house plan has 3 different floor plans: Plan A- 3 three-bedroom units, 7 two-bedroom units, and 8 one-bedroom units Plan B- 4 three- bedroom units, 4 two-bedroom units, and 8 one-bedroom units Plan C- 5 three-bedroom units, 3 two-bedroom units, and 9 one bedroom units...

Mathematical Derivation of Significant Figure "Rules" Let's say I have a scale which can accurately read weights out to ten-thousandths of a gram so it might read 1.0005 g or 0.0005 grams ... why is it that the first reading has 5 significant figures and the second has only 1? Same instrument...

Homework Statement Find the ground state of nitrogen in the form (2s+1)(L)(J), where s represents the total spin, L represents the total orbital angular momentum (s,p,d,f), and J represents the total angular momentum. Attempt at solution Well, the electron configuration is [He](2s)^2...

The question: Suppose point A is grounded (V = 0) in Figure 21-36, in which script e = 16 V and R = 11 . Find the potential at points B and C. Here is the diagram: http://www.webassign.net/walker/21-35alt.gif I'm pretty sure that I have to use Kirchhoff's rules in order to solve this problem...

Pls point out me every body. I wish to know why does the magnetic field and current are perpendicular to each other? Or is it natural phenomena?

Hi! I wonder if the Feynman rules in momentum space can also be applied to disconnected diagrams. So aussume I have a disconnected Feynman diagram 1 , i.e. the product of two connected Feynman diagrams 2 and 3. I can translate my diagrams with the position space Feynman rules to explicit...

This is not a homework problem, but advice on the presented examples would be helpful anyways. Does anyone know of a good QM textbook or website that discusses the rules for applying derivatives in QM? In reviewing many of the derivations, I find many weird applications with no reasoning from...

Homework Statement http://www.cramster.com/Answer-Board/Image/20073231626286331026398833900007956.jpg This is not problem. I just having trouble understanding the basics. Please just tell me right away, don't 'assist!' I trying to understand the right hand rule. Here are to...

Homework Statement Determine the current in each branch of the circuit shown in Figure P28.19 (attached) Homework Equations Kirchoff's Rules: \Sigma I_{in} = \Sigma I_{out} \Sigma \Delta V = 0 The Attempt at a Solution I have no idea where to begin. It's in the Kirchoff's...

in peskin-schroeder and http://www.hep.phy.cam.ac.uk/batley/particles/handout_04.pdf" the amplitude for e^-e^+\rightarrow \mu^- \mu^+ is written using feynman rules as follows -iM=[\bar{v}(p_2)(-ie\gamma^\mu )u(p_1)] \frac{-ig_{\mu\nu}}{q^2}[\bar{u}(k_1)(-ie\gamma^\nu )v(k_2)] but what...

Just as a dream, has anyone wanted to change the laws of physics? Example: F = ma^4 or something like that? If you could, what would you change and why?

Homework Statement Find the eq. constant for the reaction CH3COOH (aq) + NO2- (aq) = CH3COO- (aq) + HNO2 (aq) The Attempt at a Solution I find Ka for the reaction CH3COOH = CH3COO- + H+ and Kb for the reaction NO2- + H+ = HNO2 But what are the rules then? I try multiplying the...

not totally sure this should be in the advanced physics section. its a general test your knowledge question of everything youve learnt, so naturally i can't remember anything... a magnet of magnetic moment U is droped such that it falls down metal tube of length L. the magnet's magnetic...

I was playing checkers today with a friend and the weirdest thing happened. I was black and he was red. I had a black piece situated so that there were no possible moves for his red piece, but i could still make a move. It eventually came down to him having two pieces (one that couldn't move and...

Homework Statement Solve (e^(x^2))` , use this result to solve §5x*e^(x^2)dx Homework Equations * is multiply ` is derive 1.§e^xdx=e^x+C 2.§e^kxdx=1/k*e^kx+C 3.§a^xdx=1/ina*a^x+C (a is a number) 4.§k*f(x)dx=k*§f(x)dx The Attempt at a Solution (I'm alittle confused as to...

Kirchoff's Rules I can not find a good explanation anywhere for Kirchoff's rules. Googling onlygives me links that don't explain it well, and my textbook's explanation is lacking as well. I'll go over my textbook's description, so hopefully someone here can clarify this for me. 1...

Homework Statement Find the currents in the circuit shown in the figure attached. Homework Equations I actually have the solution worked out but I don't understand why something was done. So they chose to travel the bottom loop and the top loop clockwise in both cases. So they set up the...

Homework Statement http://img245.imageshack.us/my.php?image=physicsef4.jpg Homework Equations The change in Voltage = 0. The Attempt at a Solution Ok I have no clue where the loops go from. I want to say something like the current for I1 starts at the 10V battery in the middle...

[SOLVED] Using Kirchoff's Rules Homework Statement http://img266.imageshack.us/img266/4120/kirchoffho1.gif In the circuit, I_1 = 1.6 A. Find the value of: (a) the current I_2 and (b) the current I_4. Homework Equations Junction Rule, Loop Rule, V=IR The Attempt at a Solution Small loop...

A triangular array of resistors is shown in the figure. What current will this array draw from a 35.0 V battery having negligible internal resistance if we connect it across (a) ab, (b) bc, (c) ac? Kinda confused... just anything to start me off on the right track would be very helpful.

After a prolonged dispute that progressed through US District Court and the 11th Circuit Court all the way to the US Supreme Court, the Supreme Court finally settles whether Webster’s Dictionary’s definition of “any” should take precedence over ejusdem generis and noscitur a sociis...

I am asking this question because I did not get it clarified in any of the books I have read. What is the rule for having the quark structure of an antiparticle given the structure of the particle?Is it always OK to put bar on the quark symbols of the corresponding particle? Specifically,I...

hello I got al little bit confused about spins flipping in an EPR experiment. As far as I know, the idea of EPR is to measure the absorption of an electromagnetic wave induced by spin flips if the energy is conserved by \hbar \omega = g_{spin} \mu_B B_0. But now I heard several times that a...

[SOLVED] feynman rules Hi , It is a simple question from the book of david j .griffiths :"introduction to elementary particles" (6.11) Homework Statement (a) Is A--->B+B a possible process in the ABC theory (feynman rules for a toy theory) (b)Suppose a diagram has nA external A lines , nB...

Simple math rules seem contradictory... :( Consider this simple expression: x^8 - 16 If we wanted to write this expression as the product of two factors, we could start with something simple like this: \sqrt{x^8 -16} . \sqrt{x^8 -16} From that, we would simply get this: (x^4 -...

Homework Statement For \Deltal = 0 the transition rate can be obtained by evaluating the electric dipole matrix elements given by \vec{I} = \int \Psi^{*}_{1,0,0} (e \vec{r}) \Psi_{2,0,0} d\tau Homework Equations The Attempt at a Solution I've got the two wave functions...

Homework Statement What is the wavelength of the lowest note that can resonate within an air column 42 cm in length and closed at both ends. Homework Equations Given: l = 42 cm n = 1 Required: \lambda Analysis: l = \frac{n\lambda}{2} therefore \lambda = \frac{2l}{n}...

I am wondering whether someone can suggest a good ref or two (preferrably with worked example) on how to use Cutkosky (or whatever it is called) cutting rules in QFT to help pick out the absorptive/Imaginary part of a 1- or 2-loops diagrams. I have already tried Peskin and Schroeder, which is...

I am wondering whether someone can suggest a good ref or two (preferrably with worked example) on how to use Cutkosky (or whatever it is called) cutting rules in OFT to help pick out the absorptive part of a 1- or 2-loops diagram. I have already tried Peskin and Schroder, which is good only up...

Homework Statement The currents are flowing in the direction indicated by the arrows. A negative current denotes flow opposite to the direction of the arrow. Assume the batteries have zero internal resistance. http://img123.imageshack.us/img123/2045/599c898aa10950d7027807dyc7.th.jpg...

Should you apply the rules of significant figures when you are doing any kind of physics, chemistry, or mathematics computation? Like, for example if you are doing homework problems in your textbook, should you still follow the sig fig rules or should you only apply them in labs and measurements?

I'm quite confuse with some concepts here. The selection rules are derived from the requirements that quantum numbers must be conserved. It's OK. Then I see they give rules for so-called electric dipole transitions. I just wonder why dipole comes in here. How do you classify these kinds of...

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Can you give us the transition rules regarding four quantum no.s?

Homework Statement This is the circuit I'm working on: Homework Equations My equations are: 4.64v=-200I1-800I3 4.64v=750I3+800I2 4.64v=-200I1-750I3The Attempt at a Solution I should have a third unknown in each equation. I not seeing where I'm going wrong. I'm supposed to put this in a 3X3...

Who's watching the playoffs? Who are you rooting for? My Bulls are exciting again, so after many years of not caring about the NBA, my interest is piqued again. It's been so long since I've paid attention to the playoffs (I started watching again last year), that it seems there must have been...