System Definition and 1000 Threads

On page 50 of "From eternity to here", Sean Carroll writes that the protostellar cloud had a lower entropy than the solar system it produced. That strikes me as odd. A solar system looks more arranged than a dust cloud. When talking about entropy, someone always mentions the milk in the coffee...

This is not homework. I found this question when browsing and there is also solution but I do not understand it. This is part of the solution: My questions: 1) From equation (i): ΔT = m.a, I think ΔT refers to W - T (weight of block - tension of string). I got this from free body diagram and...

I am just confused on how to find the normal force/ FN of the first object. My classmates are saying Fgy is the exact same as Fn but I don’t get why Fgy= Fg sin theta Fgy= (20)(9.81) (sin35) Fgy= 112.5 Fgy = FN

Hi folks, very simple question, but have not been able to find an answer: Assume a vacuum pump pulls air through a pipe. Also assume that within the pipe run, there is an area with reduced cross section, creating a temporary increase in air velocity. Also assume the air is very moist, and is at...

Figure : Option of question : Solution attempt :

Hello, We make a Venturi vacuum system for recovering CNC coolant from the swarf trolley. It is a simple arrangement consisting of a venturi tube tee'd off the coolant pump and a stand-off placed at the bottom of the swarf trolley with a filter disc. Now the problem with this system is that it...

intermolecular distance means distance between particles. So, I imagine a sphere. $$\frac{4}{3} \pi d^3 = \frac{V}{N}$$ However, Griffitfhs pictures a box instead, where $$d^3 = \frac{V}{N}$$ And the difference between both models is a factor of ##(4\pi/3)^{2/5} \approx 1.8##, which is...

Suppose a blind man builds a machine that paints three apples with three colors, either red, blue or green. Once the machine has done this, are the three apples in the following superposition: or is the wavefunction just one of It feels like because the man is blind, the apples should be in...

I have tried to apply the conservation methods, but I am not understanding what the statement is asking for.

I have been using a coordinate system that is anchored on an event (rather than a speed reference) in Minkowskian spacetime. This makes it sort of a special case (no gravity or dark energy, just like special relativity) of the cosmological (or CMB-isotropic) coordinate system used to foliate the...

I have checked the program several times the program is running but the graphs I am getting is not what I was accepting soon one of the variables approaches zero I don't know why is it happening. The program I have made is below and it's in the FORTRAN language. If anyone knows Fortran can they...

If we look at system at constant temperature and volume which is galvanic cell, first law of thermodynamics states: $$ dU = dQ + dW' $$ Where W' is electrical work done by galvanic cell and Q is heat exchanged with surroundings. As far as I know electrical work is work done by electric field...

Hi everyone, for a lab I need to determine the position of the cardinal points of a telephoto lens. The focal points were determined experimentally, and the focal length given on the lens is 200mm. The principal points should be determined with f=PF. In all the textbooks, the principal points...

Hi everybody, first message on this forum ! I am building a machine for a friend who works with cardboard pulp, he is also a performance artist and would like a machine where 2 or 3 performers can activate the machine by hand with pulleys and wheels, and shred the pieces of cardboard that are...

I have read articles about the Voyager probes leaving the solar system (or not) depending on what definition is used. So, another definition - do the Voyagers have sufficient velocity to escape the Sun's gravitati0nal influence?

I've created a concept design of a subsea pumped hydro storage system, and need to use the flow rate in order to calculate power output. I can calculate the energy storage capacity using ##E = mgh##: $$E = mgh = 25675000×9.81×200 = 50374 MJ = \frac {50374MJ}{3600} = 13992 kWh$$ I've attempted...

I've been stuck at this pulley system for a while. I've calculated the force of which A pulls => FA = sin25*50*9.82 = 208.5 N But I get stuck on the free body diagram. Can someone help and explain the freebody diagram

So what I'm not sure on, is calculating the matrix elements for part (iii) with Pauli spinors and Pauli matrices, and then finding the form of the corresponding states. As I don't see how using the hint helps. The following is using the eigenvalues of the spin-operators. Provided what I...

I have a camera that take pictures of square boxes that are really close to one another. There is a light that is Illuminating the boxes but when I try and isolate a single but in my picture, I am reading higher values then what I should be. If I remove the other boxes and only do one box, I am...

The result equation doesn't fit with the familiar divergence form that are usually used in electrodynamics. I want to know the reason why I was wrong. My professor says about transformation of components. But I cannot close to answer by using this hint, because I don't have any idea about "x"...

One thing that bothers me regarding the phase portraits, if I plot a phase portrait, then all my possible solutions (for different initial conditions) are included in the diagram? In other words, a phase portrait of a system of ODE's is its characteristic diagram?

Hi, Let's call the box in green a plant. Does every plant consist of an integrator? It has to because when \overset{\cdot }{x}(t) passes through the green box, it becomes x(t). It's an operation of integrator; integrator converts the derivative back to the variable. Could you please guide me?

Summary:: Find the ratio of the number of particles on the upper level to the total number in the system. Consider an isolated system of ##N \gg 1## weakly interacting, distinct particles. Each particle can be in one of three states, with energies ##- \varepsilon_0##, ##0## and...

Hello all. I have a question about building the coherent transfer function and specifically how I would go about deriving the pupil function for this figure. I have not come across this in my class yet and am a bit stumped. Any help would be appreciated.

Context Boltzmann first defined his entropy as S = k log(W). This seems to be pretty consistently taught. However, the exact definitions of S & W seem to vary slightly. Some say S is the entropy of a macrostate, while others describe it as the entropy for the system. Where the definition of...

The attachment is the key. I wonder where the (3/8)L comes from. Can someone explain it, please? Thanks.

$\begin{array}{rr} x' & = -x - 4y\\ y' & = 3x - 2y \end{array}$ and initial values are $x(0) = 20\quad y(0) = 20$ so since $x=-x'-4y$ then $y'=3(-x'-4y)-2y=-3x'-12y-2y=-3x'-14y$ just seeing if this combined eq is ok...i think y also could have been substituted $4y=-x-x'$ or...

I calculate as follow and get a correct answer, but I wonder why the weight of the ladder 6 kg is not included in the mass (m) in the numerator. w= √(mgd/I) = √ { （42*10*1)/ [(1/12)(6)(2^2)+42*1] } = √ (420/44) = 3.06

Hey guy, I'm having problems to understand the final part of this section. The book says we have the lagrangian from one particle (106.16), then we have some explanation and then the total lagrangian is given(106.17). For me is everything fine until the 106.16, then i couldn't get what is going...

ck for typos https://photos.app.goo.gl/eRfYNAVK1jnBgSCu8 https://photos.app.goo.gl/8C9sJ9UgZbxXgP4P9 Boyce Book (a) Transform the given system into a single equation of second order. (b) Find $x_1$ and $x_2$ that also satisfy the given initial conditions. (c) Sketch the graph of the solution...

Q: Write an equation of a line that forms a system with the equation 3x - 2y = 8 that has infinitely solutions. A: 3x - 2y = 8. I believe this to be correct because it makes an identical line to one of her correct answers (6x - 4y = 16) and nowhere did it specify that it had to be new. Could...

Below is an ideal mass pulley system that we encounter in many problems under Newton's Second Law of Motion questions. Its supposed to be massless and frictionless i.e. string slips over the pulley and pulley does not rotate. In a real system, the pulley is assumed to be massless, whereas in...

$\tiny{307w.3.2.5.3}$ https://mathhelpboards.com/{http%3A//faculty.sfasu.edu/judsontw/ode/html-snapshot/linear02.html Find the general solution of each of the linear system \begin{align*} x' & = -3 x + 4y\\ y' & = 3x - 2y \end{align*} $A=\begin{pmatrix}-3&4\\ 3&-2\end{pmatrix}...

Hello, I'm working with a pully system and can't find the answer for this question on Google. I'm wondering how to calculate the load on the rope in order to determine what grade rope I should use. For example let's say I'm picking up a 100 lb box using a 4 to 1 system. Not accounting for...

In the solving portion of the textbook, the reasoning of the author in solving this problem is that the net work done on the system is zero because the net force of the system is zero. So my question is how was the system in equilibrium (net force=0)? My thinking is that since it is stated...

$\tiny{2.1.5.1.c}$ source Change the second-order IVP into a system of equations $\dfrac{d^2x}{dt^2}+\dfrac{dx}{dt}'+4x=\sin t \quad x(0)=4\quad x'(0)= -3$ ok I presume we can rewrite this as $u''+u'+4u=\sin t$ Let $x_1=u$ and $x_2=u'$ then $x_1'=x_2$ substituting $x_2'+x_2+4x=\sin t$...

Hi. I'm not sure about something related to the equilibrium points (or fixed points) of a non linear ode system solution. As far as I know, to check if an equilibrium point exists, I need to put the function of my ode system equal to zero. Then once the point is found, I can use it to evaluate...

Change the second-order IVP into a system of equations $y''+y'-2y=0\quad y(0)= 2\quad y'(0)=0$ let $x_1=y$ and $x_2=y'$ then $x_1'= x_2$ and $y''=x_2'$ then by substitution $x_2'+x_2-2x_1=0$ then the system of first order of equations $x_1'=x_2$ $x_2'=-x_2+2x_1$ hopefully so far..

$\tiny{2.1.5.1}$ Change the second-order initial-value problem into a system of equations $x''+6x'-2x= 0\quad x(0)=1\quad x'(0)=1$ ok my first step was to do this $e^{rt}(r^2+6r-2)=0$ using quadratic formula we get $r=-3+\sqrt{11},\quad r=-3-\sqrt{11}$ just seeing if I going down the right road🕶

There is a pressurized system at work that operates at 500 psi. The line is 22" in diameter. One of the valves failed at the body to bonnet connection and launched the valve (5,000 lbs) up and through the roof. I was curious if it is possible to calculate the height reached.

If a system is in an eigenstate of the hamiltonian operator, the state of the system varies with time only with a "j exp(w t)" phase factor. So, the system is in a "stationary state": no variation with time of observable properties. But the system could in theory (for what I understand) be...

Hi. I would like to use a CAS to solve systems of nonlinear equations symbolically. The JavaScript library Nerdamer can solve single nonlinear equations symbolically shown here, and I would like to use that function iteratively to solve systems. For example, if I have a system of three equations...

Hello, This question is with regards to the discussion around page 56 (1971 Edition) in Anthony French's Newtonian Mechanics. He is discussing the choice of a coordinate system where the axes are not necessarily perpendicular to each other. Here is the summary of what I read (as applied to...

I have the following equation to solve for the coefficients b: \sum\limits_{m,n=0}^N b_m b_n^* (x_{mn}+y_{mn}) e^{ ik (ux_{mn} + vy_{mn}) } = 0 which must be satisfied for all u and v in the interval [-1,1]. Here k is a constant, b is a vector of length N with unit norm ||b||^2=1, and x and y...

Wish to determine when a system of polynomials has an infinite number of solutions, that is, is not zero-dimensional. The Wikipedia article : System of polynomial equations states: I interpret the quote to mean the system has an infinite number of solutions if the Grobner basis does not have...

This image was provided, I've completed the first part of the question and got a = 4.8m/s^2 as well as T1= 24.5N and T2=34.3N. not sure about my answers though. also I don't understand the mass in static equilibrium part, can anyone explain how to solve that? Thanks.

Hello people :oldsmile: I would like to discuss one issue here. Let’s imagine that I am looking to the sphere: I can clearly see that it sphere, not cylinder, or cube, or submarine, or dinosaur. So what I see is objective truth. But how do we generally see the objects? We have got two eyes...

Find all solutions of the system of equations $s(x)+s(y)=x\\ x+y+s(z)=z\\ s(x)+s(y)+s(z)=y-4$ where $x,\,y$ and $z$ are positive integers, and $s(x),\,s(y)$ and $s(z)$ are the numbers of digits in the decimal representations of $x,\,y$ and $z$ respectively.

Let $x_1,\, x_2,\,\cdots,\,x_7$ be real numbers such that $x_1+4x_2+9x_3+16x_4+25x_5+36x_6+49x_7=1\\4x_1+9x_2+16x_3+25x_4+36x_5+49x_6+64x_7=12\\9x_1+16x_2+25x_3+36x_4+49x_5+64x_6+81x_7=123.$ Find the value of $16x_1+25x_2+36x_3+49x_4+64x_5+81x_6+100x_7$.