Modeling Definition and 554 Threads

Hey as part of my Physics undergrad in second year I have to take a module in either Mathematical Modelling or Linear Algebra (both course descriptions below) In first year I preferred Linear Algebra ( a very basic intro course) but apparently in second year its just all proof and no...

Hi I'm trying to preform a simple model of a ferromagnetic bar which has a coil wrapped around it. The bar has a 4×4 cm base and is 15 cm tall, the coil has an inside radius of 29 mm and outside radius 30 mm and a height of 10 cm. The goal is to find the eddy currents in the bar, generated...

This is not a homework question or anything assigned, but I would like some practice / assistance with modeling as we have not covered that in my DE class. Homework Statement The rhinoceros is now extremely rare. Suppose enough game preserve land is set aside so that there is sufficient...

I'm not sure if this should go in this section or the learning materials section, so please feel free to move this thread to the appropriate location. This semester I am taking differential equations. I have a totally awesome professor :) So far we have been working on linear algebra and...

Hi, I have a small project coming up, based around modeling (and perhaps building) a small Micro UAV system. Its a small device with contra-rotating blades (for stability), and I want to perhaps model the control system using simulink but I really don't know where to start! The aim is for the...

Hi, I'm a physics major working an internship for an engineering company at present. I have been trying to model the energy consumption and/or power for an elevator system. The goal is to be able to input different variables (cab weight, capacity, counterweight percentages, motor types...

How do I model a breadboard in simulator. The capacitance, inductance. For example, if I place a DIP part on breadboard, how much capacitance should I add between the pins in the model? I think the typical capacitance is 2pf for adjacent pins. What about pins that are 3 pins apart?

Hi all, I am currently working on a task which requires a decent model of evaporation rates from a pond. Water is deposited into the pond from a series of nozzles that spray droplets into the air over the pond. I have found some equations that I would like to use that model evaporation rates...

To the EE Forum, I am a new guy on this Physics Forum and this is my first post. I have downloaded a free software code, Finite Element Method Magnetics (FEMM) solver (see http://www.femm.info/wiki/Download) but it doesn’t work because FEMM is limited to solving low frequency electromagnetic...

I just had a weird thought. One qubit is a 2-d complex vector space which is isomorphic to a 4-d real vector space. Why can't we model the 4-manifold of space-time universe using one qubit?

Homework Statement Suppose the rate at which the volume in a tank decreases is proportional to the square root of the volume present. The tank initially contains 25 gallons, but has 20.25 gallons after 3 minutes. Solve for the general solution (do not solve for V). The Attempt at a...

My system is a compound pendulum hinged at some distance from one end and have a propeller mounted dc motor at the other end. I wish to position the pendulum with the help of motor propeller system. I tried but i am unable to get a mathematical model for it. I am getting a non linear model...

Hi, I would like to model static buildup and discharge. It will be appreciated if someone can point to me a direction. Thanks! Pei-Ying

Homework Statement Model the following reaction with any software. You have a gas phase reaction going on at the wall of a catalytic reactor. Homework Equations dA/dx = f1(x)*(A-B) dC/dx = f2(x)*(C-D) f1(x)*(A-B) = Const1*(D/1+D)*B f2(x)*(C-D) = Const2*(D/1+D)*B The Attempt at a Solution i...

Modeling with exponential and logarithmic functions help? Homework Statement Use Newton's Lay of Cooling, T = C + (T0 - C)e-kt, to solve this exercise. At 9:00 A.M., a coroner arrived at the home of a person who had died during the night. The temperature of the room was 70 degrees F, and at...

Homework Statement a) What can you say about a solution of the equation y' = -y^2 just by looking at the differential equation? b) Verify that all members of the family y = 1/(x + C) are solutions of the equation in part (a) c) Can you think of a solution of the differential equation y' =...

***Ugh, I'm so sorry. I think I put this in the wrong thread. It probably should be in Calculus and Beyond... I tried to delete it but didn't see that option.So my professor gave us this problem to work on but no one could figure it out. I don't know where to even start and there's nothing at...

Hello all: I'm a thermodynamicist wanting to get into transport modeling. In my reading, I have come across "operator splitting." I'm confused about exactly what this means in the context of transport modeling. This is probably a silly question, but does it refer to an advective term...

I am trying to build an index finger model but come to a problem, which I can not get over, on abduction/adduction movement at metacarpophalangeal(MCP) joint. Model description: My model is used to predict fingertip isometric force generation. There are 3 joints considered. There is two DoF...

A mass of 1 slug is suspended from a spring whose spring constant is 9lb/ft. The mass is initially released from a point 1 foot above the equilibrium position with an upward velocity of square root 3 ft/s. Find the times at which the mass is heading downward at a velocity of 3 ft/s. I found...

Hello, I am trying to model an explicit dynamics model in Ansys, to study impact of different objects. I cannot figure out how to model a composite with several layers in workbench. I have been trying to achieve this for over a week now. I was told that I can model the composite in Ansys...

1. The problem statement I'd like to use Matlab to help me model and solve a simple 2D steady state heat conduction problem: A square section duct is buried in the Earth some distance below the surface. This duct is at a steady temperature of 60 degrees C. I need to use the central divided...

I'm trying to prove why it is impossible for James Bond to open the parachute 2 seconds before impact and still land relatively unharmed. My argument is that there is no way a parachute can slow Bond from 190km/h to about 40-50km/h in 2 seconds. I tried searching the web for information on...

Hi, I am looking to model the diffusion of a particle through 2 layers using the finite difference method in matlab. I already successfully have modeled this in a mono-layer configuration, however I am looking to code it through two layers. I have two layers, one is 1 micron (1E-6) and the...

I am new to Ansys and I wish to model 3 very thin layers of different materials bonded to each other. Can someone please reply back. Thank you

Given two bodies where GM/x^2=A and Gm/x^2=a, how might one model the acceleration of either bodies as a function of time? A simpler version of the problem involves one of the masses being stationary (just for the sake of simplicity), so that GM/x^2=A and Gm/x^2=0. A more complicated...

In EE when one has 40 transistor all agree that it is to complex for a person to understand without using computer simulation. In an economy with 7 billion people and millions of groups, organizations, corporation, governments most seem to feel that simple analogies are good enough to understand...

Hi guys, I'm new to the forum, I'm a mechanical engineer but running a project a little outside my comfort zone which is to do with optics. I am trying to calculate the power density of a pulsed Nd:YAG laser but am getting in a muddle with the Average and Peak powers. The project is to model...

Basic premise: a pure tone sine wave can be modeled with a pendulum and the rate of amplitude decay can be manipulated with a friction coefficient. So... does anyone know how this is actually done? In other words if you picked a pure tone (let's say middle C @ 261.6 Hz) initiated at a certain...

Okay, please don't ask me why I would want to do the following; I'll try to explain.. I am writing a program and already have a module for computing 2D rigid-body and spring-mass (with only 32-bit integers, no less) which I've modified from Box2DLite. Now, for my application, I would like...

Homework Statement This is an optimization problem but I'm having trouble modeling the question. There is a sphere encased in a cone. The sphere has a fixed radius R and the cone has a variable height h and radius r. There is also a variable angle theta at the base of the cone. Express the...

I am trying to model the RPM at which the turbo I plan to fit to my BMW will develop the desired pressure ratio. I have determined air flow into the engine at the desired pressure ratio and have determined the rpm at which peak power and torque should arrive. I have also determined the size of...

I'm guessing it depends on how many factors/how unpredictable a subject is, what is it really? What makes mathematical finance so rigorous- requiring a phd in math/finance- while something like systems biology or pharmacokinetics only requires knowledge up to linear algebra?

Homework Statement The problem can be found here: http://alex.fangsoft.net/math.pdf I have completed Task #2, it is Task #1 that I am very lost on. Our teacher has really thrown us head first into the water with this one, I am very unfamiliar with differential equations and their...

Hello all, I am a beginenr and I need help as to how to model sin(wt) in matlab? how could i define the variale t ? I would liek to have cases for different frequencies where w = 2* PI * f and f is teh freuqency of excitation... thanks for your help

Hi, My differential equations professor wanted us to think about this problem: How would you go about modeling the rate at which water raises on a paper towel dipped into a puddle with fixed water level. I figure this would be a differential equation, but I'm not sure as to the form of...

The initial mass of fish in a lake was 7 thousand pounds on January 1st, 2001. Since the time, there was a 4-year moratorium on the harvesting on this specific type of fish. This species of fish reproduce at a rate proportional to the mass and by next year on the same date, there were 11.54...

Homework Statement The initial mass of fish in a lake was 7 thousand pounds on January 1st, 2001. Since the time, there was a 4-year moratorium on the harvesting on this specific type of fish. This species of fish reproduce at a rate proportional to the mass and by next year on the same...

We have just begun this topic and I'm really confused about how to approach questions, is there any trick or guideline for doing so? Ex: Consider an isosceles right triangle whose hypotenuse is the x-axis and whose vertex is on the y-axis. If the hypotenuse is 2 units long, we'd have...

Hi guys. I want to model the pressure distribution in rolling process and convert the pressure distribution into equivalent nodal forces. How do I do it. Please guys it's urgent. Any links would also help. Thanks

I am trying to replicate a JAVA based applet on MATLAB. Applet can be seen http://www.engr.colostate.edu/~allan/thermo/page6/EngineParm1/engine.html" . The theory behind the functions of the applet is http://www.engr.colostate.edu/~allan/thermo/page6/page6.html" . It is actually a finite...

Homework Statement A certain virus spreads through an entire population of 1000. It is assumed that the virus spreads at a rate proportional to the product of the infected and the uninfected. k=.00005 and initial infected is 250. Write and solve the diff eq for this problem. Homework...

I'm trying to model the I-V characteristics of a few diodes in LTSpice. Though doing the DC sweep I have in the picture doesn't seem to give me what I want. I'm sweeping from -80V (It's breakdown is 75V) to 2V, in 1V increments. What kind of simulation do I have to run across the diode to get a...

Hello all, I have questions regarding my understanding of NMR and the mathematics of it. If anyone would take the time to read this, I would very much appreciate it. Please bear with me, I am a beginner. Thank you! First, there is the question on how to model this phenomenon. Up till now I...

Hey everyone, This is my first-ever post on a forum, so my apologies if this is the wrong section or if this topic has been covered... Anyways, I'm trying to design an optimized propeller/generator that will be in a closed pipe, but I have no idea what kind of software to use as I've never...

...specifically forces over a distance (coulomb, gravity, etc.). Are there any plugins to do this?

I'm trying to figure out how to enter this into my calculator and get a graph, but I think it may be underpowered. I have a Casio fx-9860gii, to be clear. The problem is: y=0.0034e^-(x-515)/26,912 200 greater than/equal to x smaller than/equal to 800 Thanks for any assistance. :-)

Hello all, Ive never really worked with Acoustics before but have been looking into acoustic raditation, effects in cavitation, acoustic fields, sonar, etc. However, it has been pretty difficult to find any information on equations or modeling of the collision of the acoustic waves. The...

Dear all, This problem is on the modeling of an unfocused receiving acoustic transducer and compute the electric signal due to the pressure field. I have come up with this simple model in 2D. Basically, the transducer has a flat surface S and the surface is assumed moving in the direction...

Hi guys. I just want to know how Modeling (Mathematical modeling), simulation and Engineering Design are related. Your views are welcome. Any references and links would be appreciated. I just want to know more about the Design Process and how different processes and techniques are used for...