Equivalent Definition and 1000 Threads

Homework Statement An automobile battery has a terminal voltage of 12.8 V with no load. When the starter motor, which draws 90 A, is running, the terminal voltage drops to 11 V. What’s the internal resistance of the battery? Homework Equations I think the solution must involve finding...

Homework Statement The circuit is attached as a jpg image. How can i find the norton equivalent when both current sources and voltage sources are present? please help Homework Equations The Attempt at a Solution

Hi guys. I looking at a vibrations problem with 2 springs in it (System A). I need to find an overall value for the stiffness K to find the natural frequency of the system. I know that normally when 2 springs are in series I should get the sum of (I/Ki)^-1 which would give me an equivilant...

Im getting a new laptop sometime soon, the thing is that ms office is setting me back a bit. I was wondering if there are any free office equivalents that anyone here has experience with? I guess at most I'd use powerpoint and word if that's any help at all.

If I have a set of Probability distributions on a product space with marginal constraints, is there any way to (how to) express the same as a linear family of PD's ( i.e. all P s.t. E_P[ f_i] =a_i for some f_i, a_i )

When are two or more measures said to be measure theoretically equivalent? I have spent sometime on searching it; I am not getting it. Please someone help.

I'm trying to prove that the axiom of choice is equivalent to the following statement: For any set X and any function f:X\to X, there exists a function g:X\to X such that f\circ g\circ f=f. I was able to prove that the AoC implies this, but I'm having a harder time going the other...

Suppose that all resistors have a value of 100 ohm how to find the equivalent Resistance of these circuits, the number in these circuits indicate the areas for which we will be completing calculations. how to go over thesehttp://img155.imageshack.us/img155/8421/32990280.jpg...

Hi everyone, The practical equivalent stress in a welded part, subjected to torque and bending stresses, is the square root of the sum of the two squared shear stresses (from torque & equal shear) squared, + the normal stress (from bending) squared. Is it accepted/common to use this way to...

I've just listened to an online lecture where Susskind explained Bell's inequality () Basically he shows that classically A\cap \overline{B}+B\cap \overline{C}\geq A\cap\overline{C} Then he uses spin measurements with 0°, 45°, 90° to the z-axis for A, B, C to measure spins of an electron...

Homework Statement Find the Thevenin equivalent at terminals A-B of the circuit below. http://img5.imageshack.us/img5/1723/thevenin.jpg Homework Equations The Attempt at a Solution

Homework Statement How can you get an equivalent of tan(t) in the neighborhood of Pi/2? Homework Equations the answer is 1/(Pi/2-t) The Attempt at a Solution I tryed to use a Taylor's expansion but the problem is that tan(Pi/2) does not exist. Thanks for your help!

Homework Statement What is the equivalent capacitance of the arrangement shown in figure. (Answer is C1) Homework Equations Cparallel = C1+C2+...Cn Cseries = 1/(1/C1+1/C2+...+1/Cn) The Attempt at a Solution

Homework Statement See picture: http://img88.imageshack.us/img88/8319/87671967.jpg The answer is given as phasors I = 0.3536\angle45 Z = 2.828\angle-45 Homework Equations The Attempt at a Solution ZL = jwL = 2j Ohms ZC = -j/(wC) = -4j Ohms Can't do it by zeroing the sources as there's a...

On the first image i have to find the thevenin equivalent viewed from terminals x, x' & y, y' i get the Req as 7.32ohms but now i am having trouble calculating the vth, i have no I to calculate thanks in advance

Homework Statement Show that if a battery of fixed emf E and internal resistance R1 is connected to a variable external resistance R, the maximum power is delivered to the external resistor when R=R1 Homework Equations Power = R * I^2 The Attempt at a Solution We can think of...

Hi All Is there a proof that all blind-memoryless search strategies are equivalent? By equivalent I mean that no blind-memoryless search strategy can outperform any other in terms of time to goal and domain coverage. It seems to me that this is intuitively true. How would I go about...

Homework Statement How can one find an equivalent of 1/n^(a) in the neighborhood of +infinity? And what's the method in general to get an asymptotical development of a sequence? Homework Equations The result is: 1/n equivalent to ln(n+1)-ln(n) 1/n^a equivalent to...

What is the equivalent resistance of the circuit in Fig. P29 between terminals A and B? R1 = 5 , R2 = 5 , R3 = 5 and R4 = 1 . Note that the wires cross but do not make contact at the center. V= IRe IRe= IR1 +IR2 Series= Re= R1+R2 Parallel= 1/Re= 1/R1+R2 Re= R1R2/R1+R2 I am assuming...

Hi, Lets say the electric and magnetic fields in an closed surface (2-D) are known. Is it possible to derive electric/magnetic currents that can create these fields? We can assume that the closed surface is homogenous with constant permittivity and permeability. Is this a well known...

Homework Statement hi guys, i'm having trouble applying Kirchhoff's laws to determine the equivalent resistance of this symmetrical array of resistors (see attachment); i think there is a quick trick, using 4 current loops, but i can't remember it... nor find relevant documentation – this is...

Hi, Suppose I have the following circuit (excuse the ugly drawing): Suppose the generator is 1A and all the resistance are 1 Ohm (the values are not important). Moreover, suppose I already have all the voltages in V1, V2, V3, V4 (which I got using nodal analysis), and V0 is set to ground...

Homework Statement 3 identical resistors..give the equivalent resistance of the circuit.? The diagram can be found here: http://img27.imageshack.us/i/physicsquestion.jpg/ Homework Equations The Attempt at a Solution

Homework Statement Hi, I'm trying to solve this problem on MasteringPhysics: This circuit is given, and it says C-eq for the circuit is 9.22 microfarads: http://img143.imageshack.us/img143/3475/walker4ech21pr118.jpg The question is to find C in the figure knowing C-eq is 9.22...

A 1.2 ton air conditioner has the capacity to freeze 2400 lb of ice at 0°C in a day. What is the equivalent rate of transport of heat in watts? QH(out)= QL(in) + Wi Coefficient of Performance= QL/ (QH-QL) Coefficient of Performance of an Ideal System: TL/ (TH-TL) QL/QH= TL/TH I...

If any among you have read I.E. Irodov , you would know that there is a problem based on an infinite mesh of resistances which has squares on it. To find the effective resistance between any two adjacent points we assign a current I in ward and I outward from the other point for a given V and...

I didn't think this question would fit in any of the other forums, hopefully this is the right place... I'm not sure how many other people on this forum are familiar with StackOverflow - it's basically a question-and-answer site for computer programming where members can rate each others'...

Homework Statement Find the Equivalent Capacitance: Homework Equations c=Q/V Conservation of energy The Attempt at a Solution I made Q1 be the capacitor of 1uf, the top 2uf be the capacitor of Q2, bottom capacitor of 2uf be Q'2, capacitor of 4uf be Q4, capacitor of 5uf be Q5...

Homework Statement Find the equivalent capacitance of the picture in the attachment file Homework Equations The Attempt at a Solution The circuit is neither in parallel or series. I tried breaking it up into series and parallel but it seem too easy to be correct. Any tips on solving this?

Not really homework, but a typical exercise question, so I figured it's appropriate to post it here. Homework Statement X,Y topological spaces f:X→Y x is a point in X Prove that the following two statements are equivalent: (i) f^{-1}(E) is open for every open E that contains f(x)...

Homework Statement I need to find the equivalent resistance of the network outside the battery, and the current in resistor R2. the picture of my circuit is attached. R1= 10 ohms R2 = 6 ohms R3 = 5 ohms R4 = 30 ohms Homework Equations series Req= R1+R2... parallel 1/Req=...

http://img205.imageshack.us/img205/6923/logp.png What is the meaning of '+' above log? Is there an equivalent expression for this? Thanks

Does anyone know what is the equivalent UL level for FMVSS 302?

Hi everyone, Time for me to do another demonstration for some coworkers, and I want to make sure I'm being accurate. The idea is to explain how much force a small 2000lb car moving at 40mph has, and then explain the speed that an 8lb bowling ball would need to have the same amount of force...

Homework Statement Find the Thevenin Equivalent resistance for the network below: http://img27.imageshack.us/img27/8508/circuit.png Homework Equations R=(1/R1+1/R2)^-1 The Attempt at a Solution Hi all, to find the resistance i short circuited the volage sources and...

Two resistors are in series. Find the equivalent resistance if the values of the two resistances are as follows. a) 10 [Ω] and 20 [Ω]. b) 100 [Ω] and 1 [MΩ] (M stands for “Mega” or million). c) 3.0 [kΩ] and 6.7 [kΩ] (k stands for “kilo” or thousand). d) 400 [Ω] and 1 [Ω]. Repeat the...

Homework Statement all resistors have arbitrary values. the equivalent resistance needs be found between terminal a and b.Homework Equations I have not got a clue how to tackle this problem. as such there is no attempted solution either.The Attempt at a Solution any help would be great. chollins

Homework Statement Find an equivalent expression for sin3x in terms of function values of x, 2x, 3x, raised only to the first power. The Attempt at a Solution stuck! don't know where to begin I am reviewing for my exam right now I remember doing one of these problems before but I can't...

Hi, I found this question from a textbook: Suppose there are two black boxes, Box A has a 1V voltage source and 1ohm resistance (Thevein Circuit); and Box B has a 1A current source and 1ohm resistance (Norton Circuit). You only have access to the two terminals. How do you know which is which...

Homework Statement If the mass of a hydrogen atom is 1.67*10-27kg and the mass of an electron is 9.1*10-31kh, how many electrons would be required to have a mass equivalent to one hydrogen atom? Homework Equations The Attempt at a Solution I tried dividing them into each other...

(My previous thread on Bohm Interpretation quickly became 4 pages of mostly unrelated discussion. So I'm restarting here with more precise questions.) Okay, I've read some references on the Bohm Interpretation and I am still confused. As one paper mentioned, some extensions have stochastic...

This lab involves a spool that has a crank on it and also has a string wrapped around it several times with a mass hanging on the edge of the string hanging vertically. 4.)Suppose, the cord where it is attached to the post, is under tension during the experiment. Would this lead to error in...

1.) Using the table provided what is the change in thermistor resistance if temperature rises from 21 C to 30C? The ohm values for resistance are 120810 for 21C and 79,422 for 30C. I just subtracted the two numbers and got -41,388 ohm. I hope that's right! 2.) This lab involves a spool...

Hello, I came across a type question and my prof never went through it in the class and unfortunately I couldn't find it in the textbook nor on the internet. I can find the equivalent capicitance of capacitors in a combination of series/parallel no problem, however when a resistor is thrown in...

Okay. I have been at this for two nights now. I want to derive, step by step, the equivalent spring constant of a Beam cantilevered at both ends with a loading at its center. Here is a schematic with A=B=L/2 Now I would like to use superposition to find the deflection at L/2 due to the...

1. Let O be an open cover for [a,b] and let x=sup{d|[a,d] can be covered by finitely many elements of O}. Clearly x>a. If x<b or x=b, then there is an element O_1 of O which is a neighborhood of x, and there is an \epsilon>0 such that x-\epsilon is an element of O_1, and since there is a...

Homework Statement I don't quite understand how to read circuit diagrams, so I'm not sure how to find the equivalent resistance in some cases. What is the equivalent resistance of circuits A and B? I drew a picture to help me explain what I'm talking about: Homework Equations...

Homework Statement I am trying to find the theoretical Thevenin equivalent resistance for a black box that I used in an experiment. The measured Thevenin equivalent resistance was roughly 4786\Omega. However, I have tried several times to solve the problem, but keep arriving at a theoretical...

Homework Statement I am trying to find the theoretical Thevenin equivalent resistance for a black box that I used in a circuits experiment. The measured Thevenin equivalent resistance was roughly 4786\Omega, so the theoretical should be somewhere around that. However, I have tried several...

Hi Guys, :smile: Can someone please explain to me the logic behind the representation of 'Magnetic Hysteresis loss' as a resistance in electrical equivalent circuits?... will be extremely grateful. I have studied some info on this subject on the net. Even though the physics of Hysteresis...