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.
If I have a coil with 10 turns and a primary voltage $$V_p$$ and primary current $$I_p$$ and a single secondary coil with 10 turns, I understand the power in the secondary will be $$P=V_pI_P$$ and hence voltage and current in the secondary coil will be the same.
If I now bring a 3rd coil with...
Homework Statement
The following figure represent the traversal cut of a system with two cylindrical equal conductors of radius r0 length l at a distance d from one another and at the same distance h of a plane conductor (conductor zero). The dielectric that surrounds the conductors is the air...
When you put a mass on a trampoline it causes the trampoline to V. If you put another similar or same sized mass on the same trampoline at a great enough distance, will the curve on the trampoline/space-time look like a W or a U ?
If you can get the curves on a trampoline/space-time to look...
I have a dataframe as shown in the picture and what I am trying to do is to calculate the number of occurrences based on the values in 2 columns and then calculate the percentage of the occurrences. I have tried the following code but it gives me a zero value in the end and i don't know why...
Homework Statement
I for some reason can't seem do become sure of this.
There are 2 variables x and y. And two constants, a and c, which are both positive.
Homework Equations
x+2y ≤ (3/4)*(a^2/c)
x + 2y < a
The Attempt at a Solution
Does this mean that: (3/4)*(a^2/c) < a ?
Mons
As the title says, I would like to self-study multivariable real analysis (integration, specifically; the Riemann integral) and I need some recommendations (resources, books, videos, ...).
I'm from Croatia and got my hands on some Croatian notes about multivariable real analysis so if some of...
Greetings,
My apologies if the title is confusing; I don't really know how to explain what I am trying to do or what label this problem would fall under.
Scenario:
We have a magic bag, and inside the magic bag are an unknown/unlimited amount of coins.
There are 100 different types of coins...
Hi,
For a particle in a box (so that the momentum spectrum is discrete), we can write the identity operator as a sum over all momentum eigenstates of a projection to that eigenstate: $$I=\displaystyle\sum\limits_{p} |p\rangle\langle p|.$$
I was wondering what the corresponding form of the...
Homework Statement
Find charge on 3 capacitors.
Join two squares with one common side. At the middle of the common edge, place C3=6uF (micro-farad).
On upper edge of left square, place C1=2uF. On upper edge of right square place C2=4uF. On lower edge of left square, a battery-10V and on lower...
How do I stop multiple radio frequencies ...Micro, Infra and combined frequencies used in a sweep rotation(?? guessing here) ...from any space.
Thank you for any advice you can give. Been traveling.
For the record I thought...wearing magnets ?? I have some minimal back ground in RF but am a...
Hi all,
I'm a theoretical physics hopeful, and I've had a couple of major setbacks in my undergraduate studies. I'm thinking of whether I should pursue a career in TP, or reconsider doing physics entirely.
My background:
I've always had an interest in Physics. I got a bronze medal from...
Hi al;l, it's Mr. ALKIADT again (A Little Knowledge Is A Dangerous Thing)...in this case, my knowledge of Bernoulli effect.
I know that when a fluid passes through a restriction, the flow rate speeds up to maintain the flow rate of the wider cross sectional area behind it...so if you've got one...
Hi pf,
there was an article in the Stanford encyclopedia about QM that was rewritten.
it quoted a "multiprocess" interpretation differing from Everett's one which could be related to Bohm's interpretation. it is no more there.
i am wondering if there are interpretatins where different results...
A chord played on a piano is multiple different pitches, each at a different frequency, played simultaneously. The ear hears this as separate sounds. The cochlea of the ear is organized by tone (tonographic organization), from highest to lowest frequency. So a triad chord will stimulate three...
I don't think this is related to linear dependence/independence of linear algebra. I am talking about multi-variable calculus.
I am getting confused with being able to quickly tell which variables depend on others when there are 4+ variables involved. For example, suppose I have w(r,s)...
Does anybody happen to know the formula for resonant frequency of a Helmholtz resonator having N necks?
Physics is not my field and I'm a bit over my head. I need the formula for a computer program related to musical instruments--this is the only thing holding me up. It seems like it would...
Hey! :o
I am trying to understand the multiple grid method.
The idea is to use at each step different grids to solve a linear system of differential equations, so that we get the best approximation as possible.
It holds that the finer the discretization, the more accurate the solution ist...
From another thread:
I see this claim made fairly often, but it does not seem correct to me. According to the MWI, the dynamics of the wave function is always unitary (there is no collapse), and a unitary process cannot "create" or "destroy" anything. All it can do is entangle things. So, for...
1. A student measures the density of a metal and calculates answer to be 8543.2kgm^-1 . The result is accurate to +- 1.1%
Which of the following states answer to an appropriete number of sig figs?
A 8.543x10^3
B 8.5x10^3
C 9x10^3
D 8.54x10^3
2. Relative Uncertainty = Absolute Uncertainty/...
In general, is the number of distinct geodesics between two fixed points purely a feature of the topology of the manifold? i.e. Can there ever exist two topologically equivalent (I can’t remember the proper word right now- is homeomorphic the right one?) manifolds, ##\mathcal M## and ##\mathcal...
Homework Statement
The correct answer according to answer sheet is answer B.
Homework Equations
λn= 2L/n (both ends open)
λn = 4L/n (one end open one end closed)
c=λf
Speed of sound does not change. as it is still in air... (correct assumption? )
The Attempt at a Solution
f1= 500Hz
L =...
Homework Statement
Homework Equations
Fnet= Δp/Δt
p=mv
The Attempt at a Solution
p (before) = 0.4 x 5 = 2
p (after) = 0.4 x 3 = 1.2
Δp = 0.8
Δt = 0.2
Fnet= Δp/Δt
0.8/0.2 = 4N
Correct answer in textbook is D, I do not understand why?
Homework Statement
If Z= (1)/(z conjugate) then Z : ?
Homework EquationsThe Attempt at a Solution
let z= a+bi
the z conjugate= a-bi
(a+bi)=(1)/(a-bi)
(a+bi)(a-bi)=1
a2+b2=1
does it tell from this expresssion that the complex number is a pure real ?
Homework Statement
A scalar is given by
It is controlled by
With step time h = 0.2 s
1. Find the discrete equivalent model
2. Check the stability of closed loop (K = +1)
3. Obtain the via the Bode plot
Homework EquationsThe Attempt at a Solution
So for question 1. This is where I'm...
Spiral galaxies of course rotate around one axis perpendicular to the plane, but has anyone measured if any spiral galaxies are also rotating about an axis through the plane or about any other axis?
Hi guys,
I am newbie on thread and currently working on a project
I need some help on the Heat flow on multiple walls.
Here is the setup (see figure below)
The first wall is a Steel material which has a 350C temperature(1kwatts) and the an Air Gap is present then followed by a Plastic wall...
Hello everyone. This is my first post on this forum. Thank you for taking the time to help me with my question.
I have no idea where to start. :(
Question 1:
Find an example of a predicate P(x,y) where the domain of x and y are D such that
$\forall x \in D, \exists y \in D, P(x,y)$ is true but...
How many things can go wrong simultaneously and apparently independently with a gas central heating system? Mine has been stretching credulity to the limits last weekend.
Saturday afternoon, we noticed house getting cold and spotted that pilot light was out. Couldn't get it to relight at all...
If I have an asset that has a 10% chance to fail and I have ten of these assets in a basket, then what is the chance that one will fail in this basket? 10%?:partytime: What is the chance of 10 failing? 0,01%?
Please also explain in some laymans terms. I am a total noob when it comes to...
If I need 50,000 Nm of torque to rotate a wheel, and I am rotating it about its rim (like the London eye), would 5 10,000 Nm motors each connected to a set of tyres to rotate it (the motors are not connected to each other), or would these motors first need to be connected to each other and then...
I'm trying to understand the time delay induced on each photon when several individual photons travel in an open space from a sender to a receiver for example in the application of Quantum Key Distribution. So what I understand so far is light(photon) travel around 299,792 km (186,282 miles) per...
Homework Statement
Basically I'm trying to create two timers using System.threading.timer that run in parallel. One that runs for a minute, one that runs for a second. When I run the program I get nonsensical output. Despite reading a lot of stack overflow questions I can't seem to find where...
Hello all I'm new as I'm just revising my maths to teach irish leavers in revising and exams maths and sciences. This exam section has me puzzled hope you can help
Three digit numbers are made from the numbers 2,3,4,5,6 .. See questions and my calls below
Total number of outcomes is ...
Hi,
I am trying to understand capacitors and have come across the example in the attached image.
What I would like to understand is how to calculate the electric field at some distance x within the capacitor. With x>>R , x<R and x=R .
The image is of two circular disks as the...
The picture below shows an image of a bed from a 3d printer, which I intend to equip with an array of 15 x 3 mm Neodym magnets to hold down a steel plate. The steel plate itself is not and can not be equipped with magnets. Theres a heated aluminium bed between magnets and steel plate and the...
OK, so time is change of displacement. Speed is change of change of displacement. Acceleration is change of change of change of displacement (or of distance, sorry I'm not sure whether acceleration is a vector or a scalar). Then you get change of change of change of change etc. ad infinitum.
It...
Hi!,
I have a question for you geniuses (geniusi?)
Why are there two different equations to find the magnetic field of a solenoid and a coil with multiple turns?
(According to my textbook)
The equations for each are
Solenoid:
Coil with multiple turns:
Why are they different? Is there a...
Homework Statement
More than one options may be correct .
Homework EquationsThe Attempt at a Solution
[/B]
Options a) and c) are correct . But I don't understand how non magnetic metal reacts to the magnetic field .
Is it in some way related to ferromagnetism ? But then either both b)...
Homework Statement
More than one options may be correct .
Homework Equations
Inductive reactance =ωL
Capacitive reactance = 1/ωC
The Attempt at a Solution
On increasing the frequency , inductive reactance increases whereas capacitive reactance decreases . Thus , option a) is correct ...
Homework Statement
Hello,
Here is a multiple choice question I would like to be clarified.
Suppose that the angular momentum of a system can take the values 0, 1, 2. One carries out a measurement of ##J_z##,the state of the system will:
##a##-Be perfectly known if the result is 0
##b##-Be...
hi, i am studying about design the box carried on car.
i am really stuck in how to draw free body diagram for when 3 or more boxes stack together on car running and braking. there are many example with 2 boxes but i don't know why i can't find any case with 3 or more boxes
thanks in advance
iPTF14hls was a supernova discovered in 2014. Typically they reach a brightness peak quickly and then fade over few months - but this star had several oscillations in brightness. To make it more confusing, archives from 1954 show a supernova at the same spot.
News article
This model can lead...
Homework Statement
The object is made out of multiple parts. The inertia matrices of every part are given. Only one part is rotating. How do I find the total inertia matrix.
Homework EquationsThe Attempt at a Solution
I thought that I could sum the inertia matrices, after tranforming them to...
Is it possible to set mirrors up in such a way that if you hit any area of any of the mirrors, the laser would be brought to a central location in the middle of the mirrors? I'm thinking of a way to transmit data in space via laser where you would want a large target for the laser to hit when...
Can a supernova produce some number of stars after it explodes or will it always produce just one, single star? Can the matter it ejects form multiple stars and solar systems or will there always be just one new star and its only new solar system?
Homework Statement
A solid is bounded by the surface z=x^2-y^2, the xy-plane, and the plane x=1 and x=3. Compute, by double integration, the volume of the the solid.
Homework EquationsThe Attempt at a Solution
I know that the height is the z function and the lower limit of is x= 1 and upper...
Homework Statement
You are placed in a 2-dimensional labyrinth at a starting location ##s## and must travel to n goal locations ##g_1, g_2, ..., g_n##. Determine the optimal path using the A* algorithm.
g = goal cell, s = start cell
example input:
3 11 //row length, column length
# # # # # # #...