A model is an informative representation of an object, person or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin modulus, a measure.
Representational models can be broadly divided into the concrete (e.g. physical form) and the abstract (e.g. behavioural patterns, especially as expressed in mathematical form). Of particular importance in the modern context, conceptual models are central to philosophy of science, as almost every scientific theory effectively embeds some kind of model of the physical or human sphere.
In commerce, a model might instead reference a specific version or configuration of a product offering, rather than functioning as a representation of something else.
In taxonomic settings (e.g. biology, architecture, art) a model is sometimes a particular instance of a set of related entities (species, built structures, artistic compositions) chosen as a convenient reference point around which to build discourse; such a model is almost always chosen to typify some central tendency of the group, exemplify the group's defining characteristic, or reify the group's historical lineage.
Kinds of models include:
Question:
Develop a model for producing a repeating pattern of 8 waves, with 6 smaller waves of approx. the same size and the second and sixth waves much larger. The sketch below gives a general indication of the eight wave pattern.
(Sorry for large image)
I would like to know how to "take...
Hi everyone. I am not a physicist or scientist but this is a question I have pondered for a while now.
Everytime I see a model of how large bodies (eg Earth and sun) bend the planar representation of space (creating a "cup" or "dip") I always feel that this is not completely representative...
Hi guys,
I have the idea of putting together a model collider that fires two smashable objects (eggs or whatever) at each other and show a high speed camera footage of the objects hitting each other - this is all as an analogy of what the hadron collider does at CERN.
Any ideas what I...
Hey guys, I've recently read about the Tavis-Cummings and Dicke models and I got a little bit confused about them. They are suppoused to model N identical atoms interacting with a one-mode EM field, however the atomic operators are defined in the basis (for the case of two atoms)...
Hello,
well, I am totally new to this section of physics so my question may sound ridiculous, but here it is:
When I was reading about the Bohr's atomic model, I learned about the Bohr and Rydberg equations (E=-2,18*10^18*Z^2/n^2 J and 1/λ=RZ^2(1/n1^2-1/n2^2) as well as their proofs. Then I...
I have a problem with the calculus of magnetic moment of Li-6.
The configuration of protons is 1p_{3/2}, and the neutrons' one is the same.
I have to add the magnetic moment of uncoupled proton and uncoupled neutron.
I use the following formula for J=l+\frac{1}{2} (J is the particle...
I am looking for an equation that correlates material failure and collision speed;
so that I can better understand the effects of size and speed on model airplane crashes.
Is there an equation that correlates an object's length and speed to material failure,
for one-dimensional elastic...
Hello everyone.
I am world-building for a fantasy setting. I've had an idea and I'm not sure if it's feasible or not.
I'm trying to model a non-standard world type and I wanted to see if I'm on the right track.
The idea is for a ring world. The outside is habitable. I've already got a...
In case you have the Kahler and super- potential K,W:
K(T,S,C) = -log (S +S^{*}) -3 log ( T+ T^{*} - C C^{*})
W(T,S,C)= C^{3} + d e^{-aS} +b
with T,S,C chiral super fields, b,d complex numbers and a>0.
I tried to calculate the local F-terms arising from this. The local F-terms for the i-th...
Hi!
I'd like to understand how to model consumer demand given a price I set for a good. Therefore for a specific good I'm given the current prices of competitors and maybe some historical values for number of goods sold by competitors and me at a specific price at previous times. I would...
==from conclusions section on page 4 of Barrau Linsefors June paper==
V. REBIRTH OF THE UNIVERSE AND TESTS OF THE MODEL
In the far future, huge patches of our universe, with radii larger than the Hubble scale, will be completely empty. They will be pure dS spaces. If the model suggested in this...
In the standard model gravitron is a particle but Higgs boson is not. The Higgs field causes particles to acquire mass. Mass generates a gravitation field. Is gravitron is in any way related to Higgs boson? Is the Higgs field any way related to gravitation field?
Homework Statement
A collection of fixed scatterers ('trees') are placed on a plane at random. The trees are oriented squares with diagonals along the x- and y-directions (cf attached picture). The number of trees per unit volume is n, each side is of length a, and na^2 << 1. There are...
Hi guys, I am not economist, but can anybody tell me whether there is a mathematical model for growth in free market economy without state intervention? Where can I look them up? Thanks.
Greetings again,
So I realize my last thread: https://www.physicsforums.com/showthread.php?t=757685 became chaotic with my thoughts and un-clear writing.
I've re-did the work to make it easier for people to understand my thought process. The two questions are as follows:
7)Calculate the...
Okay, I am in need of some guidance:
7)Calculate the wavelength that corresponds to an emission of energy of 1.977x10^-19 J.
Okay, well here is my thought process initially: Change in Energy = hc/wavelength.
First question: Is 1.977*10^-19 THE change in energy? OR is that the Energy...
Homework Statement [/b]
Develop a mathematical model that would lengthen the time until the shock stabilised by the given time. T= 2.51 show mathematical analysis of the situation
d(t) = -5e^(-5t) cos (10t) is the original equation for a deflection of a rod in centimetres where t is time...
For the past week or so, me and a buddie have been trying to figure out how to make a mini-hoverboard kind of this, now it doesn't even have to look like a hoverboard we just want it to be able to get off the ground with 2 fans.
What we were going to order was all this stuff...
Hi.
I've been reading that if one places a Dp brane in a 10d space then it's possible to have a string with [11] Chan-Paton index i.e. a string that starts and ends on the same Dp brane. Since the separation of the brane with itself is 0, this string corresponds to a massless particle. Why is...
I am planning to do some work on quark fragment into hadrons, and I have heard some models like Lund Model, feynman-field model and so on.
Is there any good review articles on the topic of fragmentation model? (Recent years is better)
Best Regards!
I have a formula to get an average time that an average user spends reading a web page before going to the next one, that takes as input the number of words on the page. I want to use this in conjunction with a probability distribution to try to accurately model an 'average user' that is not...
Homework Statement
I am taking a dataset of intensity vs. frequency (which I'll call dataset I_1), and fitting it with a linear model (I_mod). I want to divide another intensity vs. wavelength data (I_2) by this fitted model to get fractional changes in the second data set compared to the...
Hi, I am trying to formulate a 2D model to calculate the temperature change over time in a composite material.
The material consists of several layers, and is heated from all edges by a known temperature vs time profile.
I was thinking of creating a finite element model.
Can someone...
Model aircraft display a wide range of aerofoil shapes, and many of these models fly despite the shape of the cross section of the wing.
Models with flat wings, cambered wings, thick wings, thin wings - all of these fly succesfully.
What is the function of aerofoil shape on free flight...
Hello, I am looking for a model of galactic star formation that I can study. Particularly, I would like one that works well for mature galaxies like the Milky Way. It also should be relatively recent as well. I am primarily interested in the yearly rate of star formation for galaxies like the...
So in a lecture I'm reading up on we are given questions to answer during the lectures with no answers, and for this particular lecture the answer has been omitted and it is in none of our textbooks.
But basically it says that a proton and a sigma plus, both have the same quark composition...
Light bending in the "hot plate" model of curvature
In the Feynman lectures, feynman describes the hot plate model of space curvature and shows that light is bent around the center of the plate, see Fig. 42-6
http://www.feynmanlectures.caltech.edu/II_42.html#Ch42-S1
However, the hot plate...
There are quite subtle gauge anomaly cancellations in the standard model.
Does anybody know a good summary about the algebraic constraints for number of fermions per generation, value of electroweak charges, etc.?
I have problems understanding the economic model. I need to write an introduction, but unfortunately cannot understand the main point. Will be grateful for any help! Thank you in advance!
Bernoulli's with Resistances -- model flow between oil filters
Hey guys,
It's been a while since I was in school and practicing this stuff daily, so bear with me please!
I'm a BSME and I want to model up flow between oil filters.
Currently we use a single oil filter with the same pump...
The heliocentric model marked the beginning of modern astronomy. But what were the reasons which led Copernicus to think that the Earth orbited the sun. I've read that his model was based on observations made by some other astronomer. Can anyone describe how he got this idea?
Homework Statement
(a) For the delta-function potential and with P<<1, find at k=0 the energy of the lowest energy band.
(This is part A of Charles Kittel Solid State Physics problem 7.3)
Homework Equations
(P/Ka)sin(Ka)+cos(Ka)=cos(ka) (note, K and k are different variables)
ε=\hbar...
Homework Statement
Hi everyone, I'm having some difficulties with my code:
1. Randomly Choose a lattice at position (x, y) within the NxN lattice
2. Why by writing "int x = int(drand48()*L);" and "int y = int(drand48()*L);" it doesn't extract the value stored at that location (x, y)?
3...
Homework Statement
Verify that the equation of the ground state energy Eo of the Bohr atom: Eo= (2pi2e4mek2)/h2
simplifies to Eo = 13.6 eV. Show clearly how the units of the different
quantities in the equation simplify to the eV.
This is all they give. Nothing more...
Dear every specialists, I heard that BICEP2's observation r=A_t/A_s=0.2 n_t=0 indicate two things:
1) n_t=0 excludes ekpyrotic cosmological model (ECM) definitely because ECM predicts n_t=2
2) r=0.2 excludes almost all current string inflation model (SIM) such as KKLMMT because this...
Hi
I am using Simple Harmonic Motion in a Matlab/Simulink model. Instead of using a motion for a simple pendulum, I decided to use a spring with a mass. The reasons for this is because my example is more like a lever attached to a pivot point and having an object at the end with a mass.
A...
Homework Statement
I'm having a slightly hard time with a topic we are studying at school 'the evolution of the universe'.
My first question relates to the Big Bang Model itself; does the Big Bang Model itself describe the evolution of the universe after the Planck time up to this point...
Homework Statement
Predict the ground state spin and parity for ^{7}_{3}Li, ^{15}_{7}N. ^{31}_{15}P.
Homework Equations
Fill up shells for neutrons and protons separately.
Shells in increasing energy are: 1S_{1/2}, 1P_{3/2}, 1P_{1/2}, 1S_{1/2}, 1D_{5/2}, 1D_{3/2}
and have...
Hi all!
I have a problem on finding the first passage time for kinetic monte carlo model.
Suppose I have a linear kinetic model for n states:
S1<->S2<->S3<->...<->Sn
where all the rate constants k_ij for transition between any two states are known. Is there any general way to find out the...
Hello,
I'm working here with a model for a diatomic molecule. The potential is modeled as two finite wells. For a given distance between the wells, the energy of the ground state will be minimized. If you move the "atoms" closer to each other, the energy rises, and if you move them away from...
Hi everyone. I'm a graduate student and am struggling with something that may possibly be trivial. So, my research is creating a mathematical model to represent a real system. I have data points from my real system that I want to compare my model to. How do I do a regression analysis and get...
Homework Statement
Please check attached image.
I am doing some op amp practice problems and I came across this problem:
I have to find the potential at the inverting input of the simple circuit model of the op amp. The op amp would be a basic inverting amplifier. I have to give the...
If I have a model with a categorical variable X1=0,1,2,3 and a continuous variable X2 and I have a regression model that includes an interaction between X1 and X2, then I decide I want to collapse X1 into an indicator variable where X1_new=0 if X=0 and X1_new=1 if X>=1, is my new model with an...
Hi!
One can easily analyze the Hydrogen Atom since it is a two body problem.
But how do you apply Quantum Theory to model atoms (such as iron) which are much larger and predict their behaviour in an environment?
My guess is that you use statistical mechanics, but I only just started a...
Homework Statement
One of my classes involves constructing a differential equation to model the freefall of the red bull sky diver Felix Baumgartner. I need to construct the correct differential equation to find v(t) and y(t) at any given time t. As stated above, I need to take the two...
Hi everyone,
I have a question on the rate constant of a kinetic model(like the one we use in describing chemical reaction). Suppose we have the following model between two states A and B:
A--(a)-->B
A<--(b)--B
where a, b are the rate constant for the transition. So the corresponding...
Hello everyone :)
I have a problem which I would love help with, very briefly I am having a model windmill built as an exhibition stand. As it's height is just over 3 metres I am being asked some pretty tough questions by the health and safety team at the show.
Specifically "what weight...