Systems Definition and 1000 Threads

Hello I have used and enjoyed the textbook: "Theory of Vibrations with Applications," by William Thomson However, many of the examples there are more civil engineering than mechanical. There are many good examples of "buildings" under vibrations (good examples, but civil, nonetheless) The few...

Hi I know that the equation of a simple harmonic oscillator is ##\ddot x + \omega^2 x=0##. The thing is that I don't know how to get to that equation in the situations given. In the first situation, I know that ##x) k(x-x_0)=m(\ddot x -x \dot \theta ^2)## ##y) N=m(2 \dot x \dot \theta)## So...

In Dynamical Systems Theory, a point in phase space is interpreted as the state of some system and the system does not exist in two states simultaneously. Can some phase spaces be given an additional interpretation as describing a field of values at different locations that exist...

The set of equations $$A = a_1 x + a_2y$$ ¨$$B = b_1 x + b_2 y$$ can be solved for the unkowns ##x## and ##y##. Does it make sense to have ##x## and ##y## be known and instead ##A## and ##B## unkown?

From what I gather, there are S-type, P-type & T-type systems, but I'm having a hard time wrapping my mind around the orbital possibilities. Would it be theoretically possible to have a planet in a binary star system where there is a daily "pre-sunrise" and a "pre (or post) sunset" due to the...

I was wondering if someone has any experience of using a "large-scale" ELN system for experimental physics (mainly)? That is, ELNs that are used throughout an organisation to ensure compliance, proper handover etc Where I work there is now a discussion about buying a site-wide ELN to replace...

Hey, first post here. So I have to classify these 6 elements under closed-loop/open-loop system and under CO2 removal/oxygen supply. I thought it should be: Closed-loop CO2 removal: Rapid cycling anime, Lithium granules Closed-loop oxygen supply: Water electrolysis, Cryogenic tanks Open-loop CO2...

I am a high school science teacher working on arts integration for thirty years in schools where many students have academic skills below grade level. I am looking for feedback.

The equations of motions for a closed system consisting of ##N## particles are: $$m_i \vec x_i'' = \sum_{j \neq i}^N \vec F(\vec x_i, \vec x_i', \vec x_j, \vec x_j')$$ $$ i = 1,..., N$$ Now if we impose the requirement that this closed system be symmetric under Galilean transformations, do we...

I've been looking over precedents for a design project and I noticed that the most commonly used systems are either steel or reinforced concrete structural systems. Is it possible for a steel structural system to be connected to a reinforced concrete structural system? If so, how does it work...

I'm working my way through Goldstein's Classical Mechanics and have followed the arguments until section 2.4 (Extending Hamilton's Principle to Systems with Constraints). In the second paragraph, Goldstein states that "When we derive Lagrange's equations from either Hamilton's or D'Alembert's...

Disclaimer: I am a physics student and I have very little knowledge of topology or differential geometry. I don't necessarily expect a complete answer to this question, but I haven't really found any reference that approaches what I'm trying to ask, so I'd be quite happy to simply be pointed in...

First I found partition functions of both the systems and hence total energies of them using above formulas. Z(A) = (1 - e-ε/kT)-1 and Z(B) = (1 + e-ε/kT) Then I equated these values to the given values of total energies. I got: For System A, T(A) = ε/kln(2) > 0 For System B, T(B) =...

Hello, I wanted to confirm a suspicion with how the Aimpoint optics work, but to do that I need to do some ray diagrams. I only ever did them with simple convex, concave, and spherical systems while at college. From what I already know of how reflex sights work, the LED is placed at the focal...

MY CONFUSION (WHICH IS WHAT THIS POST IS ABOUT): * The reason why c is not the correct answer is because unitasking just means a system that has one simulatenous user, right? In other words, a unitasking system can still be a multiprogramming system, such that one simultaneous user has the...

Wikipedia gives, "The relative velocity ##{\displaystyle {\vec {v}}_{B\mid A}}## is the velocity of an object or observer B in the rest frame of another object or observer A." Suppose the coordinate system being used in the rest frame of ##A## is has its origin slightly displaced from ##A##...

Honestly no idea how to get an answer. I found the electric field between the planes and out of it in those two cases but this didn't take me very far. The final answer is E(B)/E(A)=2. Can someone please explain why?

2u + 3v + 3w = 2 + 5v + 7w = 2 6u + 9v + 8w = 5 ##\begin{bmatrix} 2 & 3 & 3 & 2 \\ 0 & 5 & 7 & 2 \\ 6 & 9 & 8 & 5 \end{bmatrix}## We have been asked to use Jordan exchange to solve the above equations. Can someone please explain how to determine the values for r, s for the equations...

Please refer to article in Wikipedia https://en.wikipedia.org/wiki/Galactic_coordinate_system The following questions are related to the galactic coordinate system: Is the galactic center located on the galactic plane? Since our Sun is above the center of the galactic disk, is the galactic...

A problem of an isolated system's velocity in different inertial systems, in special relativity ##\ \ \ \ \ ## In the inertial reference frame ##K##, the velocity of each component of an isolated system in ## x## direction is zero at a certain time. ##\ \ \ \ \ ## The inertial reference frame...

Homework Statement: Figure shows two mutually coupled coils, for which L11= L22 = 3 + 2/3x (mH) L12 = L21 = 1/3x (mH) where x is in meters, (a) If i1 = 5 A dc and i2 = 0, what is the mutual electrical force between the coils at x = 0.01 m? ( b ) If i1 = 5 A dc and the second coil is...

Hi PF! Can anyone help me define a coordinate system for a circular arc that makes a specified angle ##\alpha## with a 90 degree wedge? See picture titled Geo. As an example, a circular arc can be parameterized over a straight line by ##s##, making angle ##\alpha##, via $$\vec T = \left\langle...

In particular I'm studying the paper "Theory of dynamic response functions of periodically modulated physical systems" by Lovesey et al. and "modulated system" are mentioned many times. My thesis advisor recommend to me reed this paper but is very confuse, any reference you can give me in...

Greetings, I'd like to simulate a complex mechanical automaton with lots of gears, cams, levers and springs. Most of the parts are going to be 3D printed except for some metal springs, rods and bearings. I want to make sure everything fits together and works as expected. Here is just a small...

I'm looking for research projects in the study of complex system, meanly applied in social and biology problems. I would be so grateful with the indication of researchers in the theme. Thanks!

Tesla+SpaceX= supersonic VTOL suborbital electric jet? “I have an idea for a vertical takeoff and landing supersonic jet.” — Elon Musk, every time the subject of electric planes comes up, to include almost never using the VTOL abbreviation for some reason that’s probably very unimportant. —...

Does anyone know a good book on master-slave schemes in dynamic systems? I'm on a dynamics book covering oscillators and it kind of glances over the topic and expects me to know it. I've done previous basic dynamics books and haven't seen it in them and checking on the internet I have found very...

Let’s ditch chemical fuel (even like scramjet, aero spike and SABRE) and venture to the future, for only thus we can become a multiplanetary species, and establish a true interplanetary/interstellar transit system. For atmospheric ascent: 1.Fusion reactor (thermal power)+Thermal ramjet...

Consider a 3-body Newtonian system with equal masses such that velocity change at a given time epoch for a single body is given by: I am interpreting that if also change per epoch such that say which means as a component. So body state information propagates in a way that one could...

Hi, I ask for a clarification about the following: consider for instance a 10 x 12 homogeneous linear system and perform Gauss elimination for the first 8 unknowns. Suppose you end up with 5 equations in the remaining 12-8 = 4 unknowns (because in the process of the first 8 unknowns elimination...

A coal fired steam plant takes in feed water at a temperature of 70°C and produces 15 tonnes of steam per hour at a pressure of 60 bar and temperature 400°C. The fuel consumption rate is 1.5 tonnes per hour and the calorific value of the fuel is 40MJkgˉ¹. Determine the power rating of the boiler...

Although I have over the years seen reports about simulations of the the Earth's moon's origin by a variety of possible mechanisms, none of these reports have ever reported the probability of such events. What is a reasonable estimate of the fraction of solar systems that have a planet of a size...

Mass = 0.12kg Initial temp = 500°c = 773K Initial pressure = 0.8 MPa = 800,000 Pa Final volume = 90L R = 287 Jkg^-1K^-1 1) Initial Volume V=mRT/P 0.12 x 287 x 773 / 800,000 = 26,662.12m^3 2) Final Pressure P2 = P1P2^1.2/V2^1.2 800,000 x 26,662.12^1.2 / 90 = 1,816,095,330 Pa = 1,816 MPa 3)...

I've taken on a new job recently where I'm having to maintain an existing application that generates a points profile to drive a CNC machine and part of it projects points from an axial plane (which represents the machine's working axis) onto another plane which (I think) acts as as a...

HiThis is most likely a stupid question, but sometimes I have to ask them... Imagine the following circuit shown in the image below; there is a ground fault in phase A and let's say the fault impedance is zero. Because of this fault; the potential, with respect to ground, of phase A is zero...

Hi All, When dealing with the kinetic theory of gases in thermodynamics, we obtain the result that the mean kinetic energy per atom is (3/2) kT. In considering different samples like 200g of liquid water or a solid cube of lead with one cubic meter, does kT still play an important role in...

HIya.. Lets just say for arguments sake that creating Artificial General Intelligent computers is only a matter of time and then when we do that Super Intelligent Computer systems will not be far behind.. I have seen a lot of talks on-line about the ethics involved and the plausibility of...

I recently came back from a cruise on MS Eurodam. The ship was equipped with two 17.6 MW Azipod propulsion systems. The captain explained a bit about them in a Q&A session, and I researched a bit more because I'm curious as an engineer. I'm sharing it here on PF for the benefit of other...

This is a question arising from the discussion in another thread. It's my understanding that among systems of natural units, the Planck units system sets not only "all three of those to 1", but also does the same with the Coulomb and Boltzmann constants, leaving the elementary charge not...

From here: From here: Peres writes on p.11: And on p.58: Note that Peres says that these issues are not yet fully understood! On p.63, Peres writes: On p.424: And on the next page: The footnote quoted by Peres says: And on p.25, where Peres introduces ensembles, he says (like Gibbs...

Homework Statement Given that ##x=\phi (t)##, ##y=\psi(t)## is a solution to the autonomous system ##\frac{dx}{dt}=F(x,y)##, ##\frac{dy}{dt}=G(x,y)## for ##\alpha < t < \beta##, show that ##x=\Phi(t)=\phi(t-s)##, ##y=\Psi(t)=\psi(t-s)## is a solution for ##\alpha+s<t<\beta+s## for any real...

Hello everyone! I would like to ask a rather comprehensive question. I would appreciate it if you could help me with this. I have started reading a chemistry textbook recently and typically in the first chapter of any basic chemistry course, you come across, measurement, unit conversion, etc...

I saw this question on special relativity on the internet: "A spaceship traveling to Alpha Centauri, at 0.95C it takes 4.5 years to get there as measured on Earth.how long does it seems to the spaceship passengers?" the answer was 1.4 years (Lorentz factor of 3.2). this answer makes no sense...

When I first learned about these subjects, I did what was intuitive to me and treated particles as if they carried potential energy. I would do this similarly for rigid bodies where I would also treat them as a particles with their body's mass at the center of mass. This wasn't helped by...

I am considering a masters in interdisciplinary engineering from Purdue with a concentration in either systems engineering or computational engineering. Is this a waste of my time and money compared to just getting an aerospace masters and taking courses in systems engineering or computational...

I am in my 4th year in a Bachelor of Science Electrical Engineering Technology (BSEET) program that leans toward electrical transmission and distribution. I have had two courses in calculus, so have briefly covered differential equations. Unfortunately, my course curriculum does not cover...

If I define the two dimensional sphere in the usual way, this gives me a metric ##ds^2 = r^2 d\theta^2 + r^2 \sin^2 \theta d\phi^2##. Can I just define a new coordinate system giving a point coordinates ##(\theta', \phi') = (\theta r^2, \phi r^2 \sin^2 \theta)##?. This gives me the metric ##ds^2...

Hi, There is a point that, in my opinion, is not quite emphasized in the context of general relativity. It is the notion of spacetime coordinate systems that from the very foundation of general relativity are assumed to be all on the same footing. Nevertheless I believe each of them has to be...