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.

View More On Wikipedia.org
Recent contents Top users
  1. V

    B Compute Angle Between Multiple 3d Vectors

    Imagine a point with n vectors (all with equal magnitude) coming out from that point that equally cancel each other out in magnitude. How would you calculate the equal angle between n vectors? For example: 2 vectors (equal magnitudes) coming from one point that cancel each others magnitude...
  2. CollegeCourt

    Split Pipe Flow: Multiple Inlets and Outlets (Bernoulli's)

    http://tinypic.com/view.php?pic=mhvarc&s=9#.WD__u_mLTIU Hey guys, So, I've got this problem, attached. I've used Bernoulli's to produce P1 + (1/2)p(u1)^2 +P2 + (1/2)p(u2)^2 = P3+ (1/2)p(u3)^2 +P4 + (1/2)p(u4)^2 +P5 + (1/2)p(u5)^2, Plugging in the values you get 82500 + P2 + 500(u2)^2 = P3 +...
  3. N

    Admissions Put down Multiple Research interests in application?

    So most application have three slots for research interests. My question is should we put down our top three or would this look like we are indecisive about what we want and should only put down one? That is, would the committee consider us for all three separately since each one has a different...
  4. X

    Find the multiple integral for a modeled problem

    Homework Statement A 12 foot light pole stands at the corner of an 8 foot by 10 foot rectangular picnic blanket spread out on the ground. A bee flies in a straight line from a point P on the pole to a point Q on the blanket. Set up a multiple integral whose value represents the average length...
  5. George Zucas

    Load Distribution of a Beam with Multiple End Connections

    Hello PF, I am trying to analyze a a beam, connected to another beam at one side at multiple locations (bad quality drawing below). The top side of the beam extends further and sit on another beam, while the shorter lower side is directly connected to another beam. They are all bolted...
  6. A

    Transfer function with multiple inputs

    Homework Statement Hi I am trying a question from an old textbook. I am required to find the transfer function with respect to the input frequency and the output frequency. Homework Equations For a closed-loop TF, then TF = G/(1+GH) but this does not involve additional inputs as in this...
  7. G

    Evenly distributed beam with overhang and multiple supports

    Homework Statement I have an evenly distributed load with overhang and symmetry. I want to express the reaction loads as a function of support distances. I did the the 3 support problem with integrating a load structure and redundant and solving for the center reaction to find the outter...
  8. G

    Distributed load with overhang and multiple supports

    I have a structure that can have 3 or more supports. It will carry an evenly distributed load with overhang. I thought I would tackle 3 supports first and solve with superposition but am getting the center support reaction to be very low and will go negative as I move the outside supports...
  9. C

    A circuit with multiple sources of voltage

    Homework Statement Solve this circuit: a) Mark all currents b) Write a system of equations allowing you to solve for the currents2. The attempt at a solution Part a) in attachment. Part b) \epsilon_1 = i_1 r_1 + (i_1 + i_2 + i_3) R \epsilon_2 = i_2 r_2 + (i_1 + i_2 + i_3) R \epsilon_3 =...
  10. D

    Engineering Circuit with multiple voltage sources

    Homework Statement a. Find the voltages Va, Vb, and Vc. b. Find the currents I1 and I2. Homework Equations Ohm's Law, Current Divider The Attempt at a Solution [/B] My first attempt was to redraw the circuit. I know that these voltages are with respect to ground. Therefore Va to Ground is...
  11. Biker

    Discharging a capacitor to to charge multiple capacitors

    Homework Statement Assume you have C1, C2, C3 capacitors and each one of them have a specific charge. Now imagine you connect them to one circuit (Just as in the picture below). Determine the charge on each capacitor after the movement of charges stop Homework Equations Kirchhoff's law The...
  12. Cocoleia

    Simplifying a circuit w/ multiple resistors & current source

    Homework Statement I am given this circuit...
  13. RoboNerd

    Multiple choice question on finding magnetic field

    Homework Statement E is the "right answer" Homework Equations B around a long wire = mu * I / [2 * pi * r] The Attempt at a SolutionOK. I know that the magnetic field lines will travel in a clockwise direction around the wire from the viewer's orientation with the current going away from...
  14. Y

    A Can Multiple Forces on a Body Be Simplified for Motion Analysis?

    Consider a free-falling object with known mass and center of mass being acted upon by four forces -- force of gravity at the center of mass, as well as three additional force vectors applied at known positions on the body. Is it possible to calculate, in closed form, the position and...
  15. H

    I Are there always multiple copies of you walking just beside you?

    Does physics say that when you are walking, there are always multiple copies of you walking just beside you? Source: Introductory Classical Mechanics by David Morin
  16. Z

    Java NetBeans:Sending multiple Messages: Erroneous sym type: Soc

    Hi, I made a program to send a message from a Server to a client on the same machine in NetBeans on a Button click. I used the following code in the button handler:private void sendMsgButtonActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: try{...
  17. Hoophy

    Factoring binomials with multiple variables p, x, and q

    Homework Statement Question: "If p and q are constants and x2+px+12 is equivalent to (x+3)(x+q), what is the value of p?" I was told that the answer was 7 but I am not sure how to reach this value myself. 2. Homework Equations I am not quite sure if this is applicable. The Attempt at a...
  18. E

    Entropy Change in a Reversible Process multiple phase change

    Homework Statement (a)How much heat must be added to a block of 0.120kg of frozen ammonia initially at 100oC to convert it to a gas at 80oC given the following information? (b) assuming this could be done using a reversible process what would be the total entropy change associated with this...
  19. X

    Why Does Connecting Multiple Ohmmeters Result in Cumulative Resistance?

    This might be a forehead-slap moment but I'll ask anyway... I'm working on a project building a panel of ohmmeters that will simultaneously measure the line-to-line resistance values a 3-phase generator and was running into trouble connecting all three ohmmeters to the three-phase measurement...
  20. Clara Chung

    What Is the Value of Point Charge q in a Square Configuration?

    Homework Statement PQRS is a square. Three point charges -Q, +Q and -3Q are fixed at P, Q and S respectively as shown. A point charge q is then placed at R and it experiences a net electric force towards S. Which of the following is equal to q? photo ...
  21. J

    MHB Possible title: Troubleshooting File Attachments on Online Forums

    a) The two surfaces defined by xz^2 + 2yz +xy^2 = 4, 2x - 7y - 3z = 2 intersect in a curve S. Find the tangent line and normal plane to S at the point (3,1,-1). b) Sketch the graphs of y = x^m and y = x^n where m and n are...
  22. A

    Multiple Source Transformations

    Homework Statement In the attached image, I'm confused on how the first circuit reduces to the second circuit. Homework Equations Is=Vs/R1 The Attempt at a Solution I know that in order to do a source transformation that I need to have a current source in parallel with a resistor or a...
  23. Rectifier

    Efficient Calculation of a Complex Sum with Multiple Components

    The problem I want to calculate the following sum $$ \sum^{5}_{k=2} \frac{k(-1)^k}{2^k} $$ The attempt I wrote ## \frac{(-1)^k}{2^k} ## as ##\frac{1}{(-2)^k}##. I was hoping that I could calculate the sum ## \sum^{5}_{k=2} \frac{k(-1)^k}{2^k} ## by multiplying the sums ##\sum^{5}_{k=2} k##...
  24. Dusan Stan

    One big propeller vs. multiple smaller propellers....

    The question is which is better from the efficiency point of view: One big propeller or multiple smaller ones? Or are they the same? My general impression is that a bigger one will have much more better efficiency as if you consider the following points: 1. lift is proportional to the area of...
  25. W

    I How to compare two data sets with multiple samples

    I have two data sets A and B which correspond to two different settings of the system. Both sets contain 5 separate lists of integers; I took 5 samples, at different points in time and location, for each set to reduce the random error in the data. How would I go about comparing sets A and B? If...
  26. B

    I Multiple time derivatives of gravitational potential

    Hello! Let's say our gravitational potential is (as usual for 2 body), $$a = -\frac{\mu}{r^3} \mathbf{r}$$. Then the gradient of this is G, $$\frac{\partial G}{\partial \mathbf{r}} = G = \frac{\mu}{r^3} [3 \hat{\mathbf{r}} \hat{\mathbf{r}}^\top - I] $$ Now if we take two time derivatives of...
  27. A

    How Does Closing a Valve Affect Flow Rates in Multi-Suction Pipe Systems?

    If I a pump with a main suction header and 4 smaller branch connections of difference sizes. Let's say for this example we have (2) 3", (1) 1", and (1) 2". Also let's say our pump is requiring 20 gal/min. The flow rate of each branch would be proportional to the area of the pipe correct? flow =...
  28. P

    B Does Schrödinger's paradox work with multiple boxes?

    I just read an article (linked below) today and found it to be quite curious and interesting. In short, physicists have taken Schrödinger's cat paradox to a whole new level by adding a second box. I’m still very new to all the ideas of quantum physics, but apparently this addition of another box...
  29. KaleLetendre

    Sin[θ+(pi/6)] Multiple values?

    Question: If cosθ=(3/5) and 0<θ<2pi determine the value of sin[θ+(pi/6)] Attempt: θ=cos^-1(3/5) θ=0.927295218 sin[θ+(pi/6)]=0.992820323 real answer = 0.992820323, -0.39282 How do i find the second value, all i can find is 0.992820323 but not -0.39282
  30. Clara Chung

    Is Potassium Hydroxide a Reducing Agent in the Reaction with Chlorine?

    1. The equation below represents the reaction of chlorine with hot concentrated potassium hydroxide solution: 3Cl2(g) + 6KOH(aq) → 5KCl(aq) + KClO3(aq) + 3H2O(l) Which of the following statements concerning this reaction is/are correct? (1) Potassium hydroxide acts as a reducing agent (2)...
  31. Hoophy

    Possible webpage title: Understanding Multiple Axes of Rotation in Objects

    So I am having trouble with this one, I was wondering if an object could have more than one axis of rotation. More than one axis of rotation goes against what I think is possible until I thought about a coin, at which point I was stumped, if the coin was rotating in the way a coin rotates when...
  32. RoboNerd

    Question on elementary statics multiple choice

    Homework Statement Homework Equations sum of torques = 0 The Attempt at a Solution So I tried to put the torques into the equation: Sum torques = mgL - T *sin(theta) * (L-x) = 0. Solving for the T gave me [mgL]/[ (L-x) * sin(theta) ]. This is not an option in the answers. Could anyone...
  33. Calaver

    Scalar Multiple of Vector - Vector & Scalar = 0?

    Note: I am not in the course where this problem is being offered; it was simply an interesting linear algebra "thought question" that I found online to which I believe I have found a solution. However, there is one step in my solution that I am unsure about, so thank you to anyone who spares the...
  34. P

    B Are there multiple ways to verify a trig identity?

    Well, are there? I thought that problems involving the verification of identities pretty much checked themselves because you know whether the steps you’re doing are legitimate or not and, of course, you know whether you’ve reached the expression you want. However, I got one of these problems...
  35. Albert1

    MHB Finding ? to Make A Multiple of 7, 11, and 13

    A=$\underbrace{22--22}\,?\,\underbrace{33--33}$ $\,\,\,\,\,\, \,\,\,\,\, \,\,\, \,\, \,\, 50$$\,\,\,\,\,\,\,\, \,\,\,\,\, \,\,\,\,\,\, \,\, 50$ find $?$ (1) to make A a multiple of $7$ (2) to make A a multiple of $11$...
  36. X

    A Generate Time Series with specific ACF and multiple LAG

    Hello Everyone, I will try to explain what am I doing here and I hope someone will understand. ACF - autocorrelation function I'm doing a research about non-parametric methods utility. How they fit and are useful in a different environment. I'm generating time series with different sizes of...
  37. JasonHathaway

    Diode Current & Output Voltage Calculation with V(1)=10 V and V(0)=5 V

    Homework Statement If V(1)=10 V and V(0)=5 V, and the voltage threshold for all diodes is 0.6 V. Determine the current through every diode and the output voltage Vo if V1=V4= 5V and V2=V3=10 V. Homework Equations Basic KCL & KVL. The Attempt at a Solution I know that the basic idea to...
  38. A

    How does lightning work? (one strike or multiple strikes?)

    I am mainly asking if it's possible for a thunder cloud to release its sorted energy in burst rather than in one strike. Like if a thundercloud had 1 billion volts would it be possible to great small sparks that allow it to shoot of 5 lighting strikes of different voltages rather than one strike...
  39. R

    Can multiple motors drive single axle (water pump here)

    I have a dilemma with the design of a device I want to build which is acquiring the correct size motor (shape & power) in my price range (even finding one within specs). I have found that the motors from cordless drills are ideal for this application (due to size, price and availability) so...
  40. O

    Other Should I apply to multiple job ads?

    I am doing my exchange studies in Sweden and have applied to two internship offers at Volvo. However, I've heard that the competition is tough (especially for non-native speakers). Application results are only for the next month. Should I apply to other internships/thesis placements across...
  41. Erik Ayer

    I Polarization entanglement - multiple tests

    Imagine you have a single beam of polarization-entangled photon pairs where photons of each pair have opposite polarization. This beam goes to a polarizing beam splitter. Of each pair, the vertical photon passes directly through and the horizontal photon is reflected 90 degrees left. After...
  42. JohnGaltis

    Multiple Lens System(Objectless and Parallel Rays)

    Homework Statement Consider a telescope composed of two convex lenses, the objective lens and the eyepiece. The objective lens has a focal length of 26cm. Rays parallel to the principle axis enter the telescope through the objective lens and exit the telescope from the eyepiece as parallel...
  43. Alpharup

    B Using multiple calculus books at the same time......

    Many people advise that we should learn concepts from only one book as using too many books lead to confusion. I have Spivak, Apostol and Kuratowski for Rigorous calculus. When I first read Apostol, I had a hard time understanding. After doing some problems in Spivak, I find the same in apostol...
  44. S

    About electricity and the EMF -- Multiple choice question

    Homework Statement The cell in the circuit has an emf of 2.0 V. When the variable resistor has a resistance of 4.0 Ω, the potential difference (pd) across the terminals of the cell is 1.0 V. What is the pd across the terminals of the cell when the resistance of the variable resistor is 12...
  45. R

    Freewheel/Ratchet Clutch - Combining multiple torque inputs

    Hi, I am required to design a tandem bike where multiple torque inputs will be present at different speeds since persons on the bike will not be cycling at the same rotational velocity. From my understanding of freewheel clutches to transmit all the torques produced by the cyclists using...
  46. Korbid

    A Evaluation of a horrible Multiple Integral

    I need to evaluate numerically this integral (second virial coefficient). At first, i want to simplify a bit, how could i do it? Now, i have a 8-dimensional integral and it's very horrible. T, k, tau0 and R are constants. r is the position and v is the velocity for two particles 1,2. r12 =...
  47. Korbid

    How to Numerically Solve a Multiple Integral in Mathematica or Sage?

    I'm trying to solve numerically this multiple integral. But i don't know how to calculate it with Mathamtica or Sage software. $$\int{e^{-(\vec{v}^2_1+\vec{v}^2_2)}e^{-E(\tau)}}d\vec{r}_1d\vec{r}_2d\vec{v}_1d\vec{v}_2$$ $$E(\tau)=\frac{k}{\tau^2}e^{-\tau/\tau_0}$$...
  48. G

    Thevenin's circuit analysis. Multiple voltage sources

    Hi, i am halfway through one of my assignments and i require some assistance. I do not seek the answer to the assignment just a little boost to my knowledge. 1. Homework Statement Basically, if i am calculating the Thevenin's voltage and the resistor i have removed that is in question has a...
  49. F

    Complex RC Circuit - Multiple Resistors

    Homework Statement I have the answer to this question, but I'm trying to understand how to do it. It's a simple circuit: https://onedrive.live.com/redir?resid=6CDEB7909E9460BA!57382&authkey=!ALscxM1v2OtHZIg&v=3&ithint=photo%2cPNG (note: Image inserted in-thread by moderator) The questions...
  50. Richa

    How can a medium carry multiple sounds at once?

    When one hears a police siren, music, and a car alarm all at once, how can these multiple types of vibrations be accommodated by the medium? (Let's take the simple case of the diatomic gases in air.) Is it possible for individual molecules to vibrate and propagate multiple sound waves at once...
Back
Top