Multiple Definition and 1000 Threads

A multiple-unit train or simply multiple unit (MU) is a self-propelled train composed of one or more carriages joined together, which when coupled to another multiple unit can be controlled by a single driver, with multiple-unit train control.
Although multiple units consist of several carriages, single self-propelled carriages - also called railcars, rail motor coaches or railbuses - are in fact multiple-units when two or more of them are working connected through multiple-unit train control (regardless if passengers can walk between the units or not).
The term multiple unit does not denote locomotives using multiple-unit train control.

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  1. B

    EM waves: multiple planar interfaces (PEC-backed lossy dielectric)

    Homework Statement Our prof has told us we can get help from wherever/whoever we want as long as it isn't classmates. This is a take-home test. The relevant question: You have a three-layer dielectric. | Layer 1 | Layer 2 | Layer 3 | Layers 1 and 3 are semi-infinite. Layer 1 is air (εr =...
  2. C

    What Happens When Multiple Slits Are Used for Diffraction?

    Hi there. It's not actually a problem, I was just trying to figure it out, so idk if this is the right section for this post, but anyways: I've managed to derive the expression for the Fraunhofer diffraction in a single slit, such that the distance between a minimum and the central point is...
  3. P

    Finding the Force on One Point Charge Due to Multiple Point Charges

    Homework Statement Two +4 mC charges and two -4mC charges are arranged on a circle of diameter "d" as shown in the figure below. The magnitude and direction of the force on the +4mC charge at the top of the circle is: a) 6.39*10^6 N radially inward b) 1.2 * 10^7 N radially inward c) 2.4...
  4. U

    Pressure across multiple closed feedwater heaters

    Doing a T-s and P-v diagram from a real power plant Rankine cycle. The cycle, after the condenser, goes through one pump, and then in series: gland steam condenser 4 closed feedwater heaters 1 open feedwater heater another pump 2 closed feedwater heater boiler Temperature and...
  5. U

    Multiple closed feedwater heaters in series

    Homework Statement Doing a T-s and P-v diagram from a real power plant Rankine cycle. The cycle, after the condenser, goes through one pump, and then in series: gland steam condenser 4 closed feedwater heaters 1 open feedwater heater another pump 2 closed feedwater heater boiler...
  6. K

    Chemical Equilibrium with Multiple Kc

    Homework Statement Compound A can react to form B and C according to the following A<->2B Kc=1 A<->C Kc=1 If 1 mole of A is solved into 1 litre of water, what will the concentration of A be after equilibrium has been reached?Homework Equations ICE-tables(?) A<->2B+C Kc=([B]^2[C])/[A] The...
  7. B

    Luminance and illuminance of multiple point light sources

    Since there was some confusion previously where this post was mistaken for "homework" let me underline now *** THIS IS NOT HOMEWORK *** I've finished university 20 years ago, so this has nothing to do with any schoolwork or anything like that. I'm simply trying to understand some papers I'm...
  8. T

    How Do You Simplify Complex Derivatives in Calculus?

    1) f(x)=\frac { { x }^{ 2 } }{ \sqrt { x+1 } } \\ f'(x)=\frac { 2x\sqrt { x+1 } -\frac { \sqrt { x+1 } }{ 2 } }{ x+1 } \\ f'(x)=\frac { x(3x+4) }{ 2{ (x+1) }^{ \frac { 3 }{ 2 } } } Can somebody show how you can get from the second step to the third step? I tried factoring x+1 from the...
  9. Duderonimous

    Multiple choice conceptual question on the photoelectric effect

    Homework Statement In a photoelectric effect experiment, the frequency of the light is increased while keeping the intensity of the light constant. What effect does this have? A) fewer electrons will be ejected B) more electrons will be ejected C) the same number of electrons will be ejected...
  10. S

    Solving Trigonometric Equations with multiple solutions

    Homework Statement Solve each equation for solutions on the interval 0 ≤ x ≤ 2∏. 2 sin x = √3 The Attempt at a Solution Okay so I was able to solve this one: 2 sin x = √3 sin x = (√3) / 2 So i got x = ∏/3 ; 2∏/3 ; 4∏/3 ; 5∏/3 I substituted the x's into the original...
  11. J

    Solving by substitution for multiple variables

    Homework Statement I have four equations and have four variables. I need to solve for each of the variables. I am having difficulty figuring out how to do this. My equations are here. http://imgur.com/EOA8I Homework Equations \frac{(x-h)^2}{a^2} + \frac{(y-k)^2}{b^2} = 1 The Attempt...
  12. A

    Change of Variable in multiple Integrals

    Homework Statement Let D be the triangular region in the xy-plane with the vertices (1, 2), (3, 6), and (7, 4). Consider the transformation T : x = 3u − 2v, y = u + v. (a) Find the vertices of the triangle in the uv-plane whose image under the transformation T is the triangle D. (b)...
  13. W

    Torque multiple choice question needing explanation

    Homework Statement If two forces of equal magnitude act on an object that is hinged at a pivot, the force acting farther from the pivot must produce the greater torque about the pivot. a. False b. unable to decide without knowing shape of object c. True Homework Equations T=rxF...
  14. trollcast

    Multiple resistors not in series / parallel

    Homework Statement Circuit as shown: (sorry about the amazing paint skills) The pd is being applied from A to B (C is in the centre of the circle) (1) Determine the relations between the current by reversing V and using symmetry or by any other suitable method (2) Calculate the total...
  15. R

    Wave function of multiple particles

    When dealing with n-particle systems that are identical, is the superposition of them just a mathematical construct, or is it similar to how the state of a single particle can be in multiple eigenstates until its measured. For instance, if I have two fermions: \Psi = \Psi_a(x_1)\Psi_b(x_2) -...
  16. C

    Point estimate from multiple sampling distributions

    Dear all, I hope someone can help me. I have two experimental groups, A (n=5) and B (n=8) containing biological samples. The samples are used to estimate my parameter of interest, θ. I do this with Markov-chain Monte-Carlo, which gives me a posterior distribution of θ for each of my samples...
  17. D

    Need help deriving multiple quantities

    Need help differentiating multiple quantities Homework Statement f′(x) = (x − 1)(x − 2)^2(x − 3)^3(x − 4)^4(x − 5)^5 I need help in trying to differentiate this equation. I know could use a combination of the chain and product rule to figure it out, but my teacher said that doing so would...
  18. S

    Question about multiple regression analysis

    Homework Statement My question is q.3 in the attachment. I don't really understand the scenario of the question. The Attempt at a Solution For (a), if X = 1, will the model become: y = (b_1)(E_1) + epsilon? So (b_i)'s are the slopes of the models? But what is the assumption of the...
  19. S

    Multiple Slit Interference - 3rd Slit Added Between 2 Slits

    Homework Statement Suppose a third slit of the same width were added halfway between the original two slits. (the original two slits were a distance d apart). When there were just 2 slits, the point C was the center (a principal max), point Z was the first maximum after C, point Y was the...
  20. A

    QM Puzzle: Can One Particle Have Multiple States?

    I was taught that a particle is assigned to a unique quantum state. As a specific example, two bound electrons can't have the same quantum numbers in an atom. And likewise one and only bound electron is assigned to one quantum state in an atom. Yet, I am reading several solid state books and...
  21. N

    Find the exact volume of a bounded surface. Multiple Integrals.

    1. Ok, so the question is.. Find the exact volume of the solid bounded above by the surface z=e^{-x^2-y^2}, below by the xy-plane, and on the side by x^2+y^2=1. 2. Alright. So, I know that I can use a double integral to find the volume, and switching to polar coordinates would be simpler...
  22. T

    KVL question for multiple loops

    Hi, The picture below is part of the notes given to us by our teacher. In case it doesn't work, it's a double loop with a voltage source on the left arm, a resistor (R1) on the middle arm, and two resistors in series (R2 and R3) on the right arm. all the resistors and the voltage source are...
  23. F

    Multiple in-phase AC sources to a load

    I'm trying to figure out how multiple AC sources which are in phase would be able to be used sequentially to power a load. This all started as I read some literature about solar PV panel systems which had a wiring diagram to tie output from the inverters directly into the electrical panel split...
  24. S

    Matlab: creating a table of equations using multiple variables

    Homework Statement I have an equation that looks like func=sin(pi*x*n)*sin(pi*y*m) I was wondering if there was any method (possibly involving for loops) where I could get a plottable function along xy for all the different combinations of n and m i.e. m= 1 n =1 so the function would be...
  25. turbo

    Italian seismologists convicted of multiple manslaughter.

    Looks like a good field to avoid in Italy. Especially in areas where mud-brick walls abound. http://www.bbc.co.uk/news/world-europe-20025626...
  26. M

    Multiple choice, magnetic force on the particle

    Homework Statement Homework Equations The Attempt at a Solution I know that since the charge is negative qo*Vperpendicular would be traveling in the oppsite direction. Which by the right hand rule ultimately affects B. So using the formula F=q0V(perpendicular)*B...
  27. M

    Conjecture: There exists no number k s.t. k^2+2 is a multiple of 7

    Hey everyone, I was doing a problem in my Discrete Mathematics book and it called for finding an infinite number of counterexamples to the statement "7n+2" is a perfect square (which fails for n=3 at least). In my search for such an infinite counterexample, I tried to find A, n=n(k,A)...
  28. M

    Multiple choice Current through Bulb A

    Homework Statement Homework Equations The Attempt at a Solution First I originally tried using kichhoff's rules, but didn't get far. What is throwing me off is they are giving me the current of the battery instead of the voltage. Since I know circuits in parallels all have...
  29. B

    Finding Inverse the Function of multiple variable functions

    I understand that given two functions f:X→Y and g:Y→X, to say that f is the inverse function of g means g o f:X→X is defined by g(f(x))=idx and to say g is the inverse function of f means f o g: Y→Y is defined by f(g(x))=idy I understand how to find inverses of one variable functions and...
  30. N

    Reference Frames? Putting multiple perspectives in kinamatics in 2D problems

    Homework Statement I have this assignment on where I have to make up a scenario and solve for the question. The question is that there is a baby that is being thrown out of building into a moving car, (to keep the baby out of harms way). How fast would the car have to traveling to catch...
  31. L

    For part b, I am lost.Multiple Pulleys: Solving Physics Problems

    Multiple Pulleys! Homework Statement A 60 kg mass and a 10 kg mass are attached together by massless inextensible strings which pass over light frictionless pulleys. One pulley is free to move while the other is fixed. a) The system is initially held at rest by means of a force supporting the...
  32. C

    Plotting Multiple Equations on One Graph in MATLAB?

    Homework Statement Does anyone know how to do this? Let's say I had the equation: f(t) = |2t, 0≤ t < 2 |(t^2)-3, 2≤t how would you plot this over 0≤ t ≤4 in Matlab? Homework Equations - The Attempt at a Solution I've tried ezplot but i can't manage getting both...
  33. D

    Can there be multiple power series representations for a function?

    I guess this is a simple question. Say I am tasked with finding the Taylor series for a given function. Well say that the function is analytic and so we know there's a taylor series representation for it. Am I gauranteed that this representation is the only power series representation for it...
  34. F

    Resonance Frequency of Circuit Involving Multiple Inductors

    I have two inductors and a capacitor in series, in the order of inductor, capacitor, inductor. I'm not sure if the equation L1+L2+k*√(L1*L2) will work in this case or not, given the inductors are separated (or offset) electrically from each other by a capacitor. So I guess my question is, can...
  35. N

    Multiple choice question on the absolute uncertainty?

    An experiment is performed to determine a physical quantity and 10 trials are made. The absolute uncertainty in the quantity can be given by a. the mean of the data b. the standard error of the data c. None of the above I'm leaning more towards b because absolute uncertainty has to deal with...
  36. U

    Multiple Electron Spin Measurements

    Homework Statement The z-component of the spin of an electron is measure and the value h-bar/2 is found. Immediately afterwards, the spin along a direction making an angle θ with the z-axis is measured. What are the possible outcomes of this second measurement and with which probabilities do...
  37. P

    Faraday's Law of Induction - Current in Multiple Wires

    Homework Statement A 7.40 cm diameter coil consists of 15 turns of circular copper wire 2.3 mm in diameter. A uniform magnetic field, perpendicular to the plane of the coil, changes at a rate of 7.29×10^−3 T/s . Determine the current in the loop. Express your answer using two significant...
  38. B

    Effect size in multiple regression

    Hello, I'm using this this calculator to determine a rough sample size for a multiple regression (20 predictors). http://www.stattools.net/SSizmreg_Pgm.php I don't really understand the effect size? Could somebody tell me if you are using multiple regression (with 20 predictors)...
  39. 0

    Visualizing Real Images and Multiple Reflections: Questions Answered

    Hi, I realize that this might be kind of a silly question, but I am in a physics class currently and I'm having the hardest time visualizing what exactly is happening when a 'real image' is formed on the same side as the object (as in the case of an object emitting light on the concave side of...
  40. K

    Finding the maximum height given multiple variables

    Homework Statement A 4.27-kg object is thrown vertically upward from the surface of Mercury, where the acceleration due to gravity is g1 = 3.70 m/s2. The initial velocity is v1, and the object reaches a maximum height of y1. What is the maximum height, y2, if the object is thrown with a...
  41. K

    Doppler effect and multiple independant sound sources.

    If I am stationary and a sound source moves towards me at a constant velocity, I will hear it (the sound) increase in frequency until it is adjacent to me and then as it moves away from me, I will hear a decreasing frequency. Fundamental stuff right? It works with radio waves and light which is...
  42. L

    Java Compiling multiple paged java project

    i have been learnin java for about two weeks. i have gone through simple programin and some other programs includin GUI through swing. till that i was working with single form programs that can be compiled by using "javac" and executed by "java" syntax.now to try better i downloaded a java...
  43. B

    Problems with propagation of error for multiple variables

    please help by telling me whether my approach to solve the problems are right or wrong. please refer to the ATTACHMENT for the questions and my approaches... your help is highly appreciated!
  44. B

    Multiple regression, why use categories

    Hello, I have a question regarding multiple regression. I am reading a paper in which the author performed a multiple regression to predict the energy consumption of an electric car based on a 27 variables measured during journeys, such as speed and acceleration etc. The author...
  45. C

    Finding the product of multiple normal distributions

    Hi all, I've been working on a little side project, but I've hit a road block on the maths for this one. Basically if you imagine a sealed pack of 10 cards, there is a 20% chance that the pack contains one foil (more valuable) card. The mass distribution of the foil cards are (heavier and)...
  46. M

    AP Physics B Course Description Multiple Choice #3-4

    Homework Statement http://apcentral.collegeboard.com/apc/public/repository/ap-physics-course-description.pdf Page 45 Homework Equations sinθ = opp/hyp tanθ = opp/adj cosθ = adj/hyp G ≈ 10 m/{s}^2 The Attempt at a Solution I know that the weight is a force pointing downwards...
  47. N

    Why Does Pressure Decrease with More Outlets in a Fluid System?

    Hey, so my situation is a positive displacement pump churning out 30gpm. Theres a bunch of pipe losses that I can deal with, and then a long 1.5" pipe with 8 possible outlets (you can screw on a hose). When one hose is attached the pressure is a we will say P1 (read from a gauge on the 1.5"...
  48. G

    Proving p is multiple of 3 iff p^2 is

    Homework Statement Prove that p^2 is a mutiple of 3 ⇔ p is a multiple of 3. We are told p is an integer. The Attempt at a Solution If p is a multiple of 3 then p=3.a (aEZ) and p^2 = 3.(3.a^2) which is clearly a multiple of 3 Suppose p^2 is a multiple of 3. Then P^2 = 3.a and...
  49. I

    Integral with multiple answers

    The question is ∫3cos25x dx. I tried to solve it 2 ways and got two different answers. Method A. ∫3cos25x dx =3∫cos25x dx u=5x 3∫cos2u (1/5)du/dx dx The 2 dx cancel out leaving 3∫cos2u (1/5)du= 3/5 ∫cos2u du= 3/5 ∫(1/2 + 1/2 cos 2u) du= 3/5( (1/2x)+∫1/2 cos 2u du)= 3/5( (1/2x)+1/2∫ cos 2u du)=...
  50. P

    Does volts and amps get at half while charging multiple batteries?

    Hi guys (and gals) Say, i have a solar panel rated at 100w 12v with the following specs: Short circult current(Isc): 6.01A Open circuit voltage(Voc): 21.5V Optimum operating current: (Imp) 5.52A Optimum operating voltage: (Vmp) 17.78v Maximum power: (Pmax) 100W And I decide to...
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