Model Definition and 1000 Threads

My son is in year 7. I received a test paper and his answers. Unfortunately, we don't have the correct answer for some questions. I have attached the screenshot. The topic is particle model (year 7). I would appreciate your help. This is not a homework question but I need your expert advice so...

Hi. I'm trying to derive Snell's law from a mechanical model: An axle of length ##d## with two wheels that run at speeds ##v_1## or ##v_2##, depending on the medium they are in (##v_1>v_2## for the moment). The ##x##-axis is the interface, ##v_1## for ##y>0## and ##v_2## for ##y<0##. The wheels...

obtaining a mathematical model for a two wheels pushed tractor

Hello,There is a model which tunes a plane wave using certain expressions which resembles the spherical to cartesian coordinates. There are two types of definitions: propogation normal and electric field vector. Why they put in propogation normal exactly the spherical to cartesian to represent...

Hello everyone, I am making a model rocket and want it to be as stable as possible I was wondering what is the most effective stabilization method for a small model rocket. I was thinking of spin stabilization.

TL;DR Summary: Applied mechanics, mechanics, optimization, dynamics, kinematics Hi, I'm trying to finish this assignment and I'm not completely sure how to proceed. Should I first create the constraint equations, then the kinematics to get the derivatives for velocities and accelerations...

https://theconversation.com/what-is-model-collapse-an-expert-explains-the-rumours-about-an-impending-ai-doom-236415

Hi. Now I am working on my term paper on "Influence of constructive elements of electric guitar on its sound" and faced with the task to build a mathematical model of instrument sustain. So far I have not found any good source that would help me with this. Now I have this formula: But I don't...

Hey guys, I'll try to be as direct as possible. So for school i'm doing an experiment at home trying to find out if the diameter of a pot affects the time it takes to boil water inside the pot as it says in the title. I had three different pots with three different diameters. I got half a liter...

I first solved for the extension of the spring when its at equilibrium w/ the mass. I got Δx = 0.122m. I thought that if I added this with 0.1m, this would give me my amplitude. I then set 0.5m as my c value and plugged the rest of my values in from there. What am I doing wrong?

See above.

I'm building a model as shown below (side, front, back). In order to measure its air resistance I will be mounting it on temporary ice blades (Green) and driving it down a long skating rink. The model has a pressure sensor incorporated into the motor / propeller assembly and a GPS unit to...

This model diagram is possible when index0/index1=index1/index2=radius2/radius1 for the model's variables. 30 degree wave into a sphere. Reminded me of something out of that old science fiction movie, The Day the Earth Stood Still...

The article https://phys.org/news/2023-07-age-universe-billion-years-previously.html#:~:text=42-,New%20research%20puts%20age%20of%20universe%20at%2026.7%20billion%20years,as%20old%20as%20previously%20believed&text=Our%20universe%20could%20be%20twice,%22impossible%20early%20galaxy%20problem.%22...

I ask for help in interpreting this question. Thank you !

Homework Statement: I am trying to write a Python code to do a project about smart parking system. I want to create a Mask RCNN model to detect the vehicles in the parking slots. My code is attached below, I got an error in the last line (creating Mask_RCNN model) and do not know how to solve...

Currently it's a very hot topic, so it would be nice to have a thread on this. Those who never heard of it may start from https://en.wikipedia.org/wiki/Sachdev–Ye–Kitaev_model A good review is https://arxiv.org/abs/1711.08482

I would like to model squeezed light and its evolution (such as when passing through lenses after being generated) using optics software such as OptiFDTD or ZEMAX. However, I don’t see any way to make such states…my plan was to simulate an Optical Parametric Amplifier to generate these states...

Question: My Answer: Is it correct? Thank you

I am trying to train a model to generate images, I have a dataset of over 17K of men posing. I have been training my model for a few hours now and Sadly all I am getting is this: Also my d_loss=-9.79e+3 how is it Negative ? here is my code: # -*- coding: utf-8 -*- """BigGANModel.ipynb...

I'd like to proceed in a linear fashion, taking each part on one by one. For the first part, we can write the Hamiltonian as ##H = \sum_{n}^{N} w(c_{An}^{\dagger}c_{Bn}+c_{Bn}^{\dagger}c_{An})+v(c_{Bn}^{\dagger}c_{A(n+1)}+c_{A(n+1)}^{\dagger}c_{Bn})##. We can convert the creation and...

Hello, I have been pondering on the following: we have data for blood pressure BP (response variable) and data about age and gender (categorical variable with two levels). We can build two linear regression models: $$BP=b_0+b_1 age+b_2 gender$$ $$BP=b_0+b_1 age$$ The first model does not take...

I want to fine-tune the Pixel2Style2Pixel model with my custom data set, but I keep getting an error when I'm trying to load in the pre-train weights. Here is my code : # Load the pre-trained model os.chdir("/content/pixel2style2pixel") from models.psp import pSp config = { "lr": 0.0001...

LBM model for phase change- relevant equations found here. Also here. #Thermal LBM #solves 1D 1 phase phase-change #D2Q5 Lattice nx=100 # the number of nodes in x direction lattice direction ny=5 # the number of nodes in y...

ClearAll["Global`*"] (*R = reds, G = greys*) (*S = susceptible, I = infected, R = recovered*) tseries = {t, 0, 3}; vars = {HG[t], HR[t], SG[t], IG[t], RG[t], SR[t], IR[t], aG[t], qG[t]}; b = 0.4; (*natural mortality rate, both species*) \[Beta] = 0.7; (*rate of virus transmission*) aR =...

I did some research online and found that "When certain elementary particles move through a magnetic field, they are deflected in a manner that suggests they have the properties of little magnets." To explain this phenomenon, physicists invented the concept of spin. So far so good. What I...

A minimally coupled scalar field can model a cosmological fluid model where And where the equation of state can be the standard ## \omega = \frac {p} {\rho}## I can see how this does a fine job modeling matter, because as the scale factor increases, the density will go as ##\frac {1} {a^3}##...

For those who have built those small model rockets, please help me understand a very very simple physics problem that i for some reason do not fully get. Why is it that the motor tube does not have a retention ring on it, to prevent the motor from flying out the nose cone? i know it cant be...

Homework Statement:: Model for Gravity Relevant Equations:: Rg -Rg = G/(8pi*c^4)T The rubber table model for gravity can't quite translate to reality. One sees that a ball placed on the table distorts it, but this is due to it being in a uniform gravity field. Just what mechanism distorts...

Ok, i have some rocket data from a 20,000 foot launch. I have the times, altitudes, and velocity at said time. Is it possible to find the terminal velocity from this long list of numbers? I tried graphing the velocities to see where the curve flattens out, since usually that is where terminal...

What is the oscillator model in a generalized Snyder scheme？How to derive the formula？

In my system I am trying to represent two lenses. L1 with focal length f1=910mm and the other lens, L2 with focal length f2=40mm. These lenses are space such that there is a distance of f1+f2 between the lenses. I have a unit amplitude plane wave incident on L1. My goal is to find the...

Suppose the EPR* concept were true as it would be applied to entangled photon polarization. (Please note: I am not saying it is.) They thought QM was incomplete, because there must exist "elements of reality" (hidden variables) that supplied the highly correlated results on entangled particle...

If some variables of a logistic regression models are non significant, should they be considered for a risk index calculation? Should the logistic model include only relevant variables? Thanks for the attention.

Continue reading...

Hi all, We are doing some work with Eaton 760 series fixed displacement hydraulic motors and are looking for a better mathematical model for the torque output. Does anyone know a good place to look? Something that includes differential pressure and temperature would be ideal. Thanks Ed

Question, if i record a video of a model rocket launching, and then falling, is it possible to get the actual (or extremely close) velocity every 1 second? thanks

Continue reading...

Continue reading...

Hi everyone, I'm an electrical engineer working on making a linear model for a power take-off system. I've gotten inertial, friction, and hydraulic/electric components done, but what is really confusing me is the gas system; I haven't taken ANY thermodynamics. To simplify it, it is modeled as a...

TL;DR Summary: Given a pentaquark: (a) Determine the isospin multiplet it belongs to. (b) Calculate a kind of a Gottfried Sum Rule for this pentaquark-neutrino or -antineutrino scattering. Hello everybody, I'm having a bit of a trouble with the exercise below as it deals with a pentaquark and...

Hello together, I need help for my bachelor thesis. We want to simulate the mechanical properties of polyurethane foam using the Gibson-Ashby model in Abaqus. So I would like to know if there is a library or something similar for Abaqus. I'm fairly new to Abaqus and the Gibson-Ashboy model, so...

I just launched a 2.2kg model rocket that stands about 5 feet tall and has a airframe that is 4 inches in diameter. I am trying to find how much the impact force is when the rocket hits the ground at 16MPH. Whats the best approach? Momentum? KE? or something else:) thanks

Why do they say uniform conductor? Many thanks!

I have studied up to now about forecasts to constrain cosmological parameters in the context of CPL( Chevallier-Polarski-Linder ) parametrization with w_0, ,w_a parameters in equation of state for cosmic fluid. For this, I have used Matter power spectra ("fake data") generated by CAMB and CLASS...

That quote be true, yet we are so different. The quote is from a Freakonomics Podcast. That led me to the web site https://geerthofstede.com/culture-geert-hofstede-gert-jan-hofstede/6d-model-of-national-culture/ I think that these cultural differences and the insights they provide are very...

As this week the great topic is the Einstein-Rosen bridge and duals of it, I wonder what happened with the interpretation of Connes NCG model as two sheets of spacetime whose separation is measured by the higgs field. How is it different of a ER bridge?

[FONT=Calibri]Assuming the Sun’s core has a mass of 0.35 Msolar_mass and taking values for other quantities from a internet background search or from the following figures (i.e.: Radius "solar core" = 0.25 Rsolar_radius ): ------------------------------------------------------------------------...

I created a model of spacetime based on an extension I added to the principle of relativity. I then derived the coordinate transformations which preserve the speed of light in all frames, which are different from the Lorentz transformation. I worked out the formulae for energy and momentum, and...