Modelling Definition and 288 Threads

Hi! I've been trying to model the Saturn V's velocity using Tsiolkovsky's ideal rocket equation, and in the process, I think I may have made a mistake with regards to the specific impulse? I've come up with the following equation, taking the change in gravity into account. (a(t) is the...

Hi. I will soon wrap up my physics bachelor and have lately been considering specializing in modelling of ice thawing and freezing processes. What types of math and physics are involved in those kind of processes and what subjects should I make sure I know. What classes would be useful...

Homework Statement I'm currently writing a program that will read in a list of gaussian distributed random numbers as an array and will make a 'measurement', that is they will be assigned to another array with an associated error. This is to try and simulate the communication of Alice to Bob...

Hi guys, just an intuitive question I've come across. Quite ambiguous, not sure on the correct response. So basically I'm given a scenario where I'm provided the data of an actual height vs time points of a vertical ball drop and it's bounce up and back down etc. Question starts off where I...

For the probability of the number of infective's increasing in one time step, I found the answer is: ∆tβi(N-i)/N where β is the contact rate, ∆t is the time step, i is number of infectives,N is total number of susceptible's and infective's I can't quite see where this is coming from. β is...

One way to model the wavelike property of a trapped particle is to have it do something (say expand and contract) on a periodic basis as it travels though space. Assuming the periodic expansion and contraction matches the wavelength of the particle, it will "interfere" with other particles the...

Hey Folks, I'm working on a new problem in a field I don't have much experience in at all and looking for some high level guidance to get me started. For a certain material I want to calculate how much that material ablates in the presence of steadily increasing radiation flux from the...

Is there an equation in which you can model the flight path of a golf ball? I know there must be as there are plenty of "Golf Ball Flight Simulators". Does anyone know of this equation? Would be quite helpful to me.

A light-weight "pop-up" tent consists of six flexible plastic struts that are inserted into pockets sewn into the joins of the fabric panels. The resulting shape has hexagonal horizontal cross-sections, while vertical cross-sections through the centre are semi-circular. Derive a formula for...

I have an actual flyback converter on a chip and I'm thinking of having a simulation platform to model the circuit on MATLAB. This is because somewhere down the road I intend to modify the inductor by biasing it with a permanent magnet in order to prevent premature saturation. It is hoped that...

On a stretch ofsingle-lane road with no entrances or exits the traffic density r(x,t)is a continuous function of distance xand time t, for all t > 0, and the traffic velocity u(r) is a function of density alone. Two alternative models are proposed to represent u: (i) u= uSL (1 – r^n/...

Traffic Flow Modelling, I really confuse and do not how to start :confused:.

I am trying to find a description of sound waves and speed of sound in gases using Kinetic Theory. I mean to derive the sound waves in a medium like gas , composed of molecules moving and colliding as Kinetic Theory describes. The origin of the sound wave, as our experience shows, is the...

Homework Statement consider s dipole with spacing of 2cm between the two sources. it is radiating a 100hz pure tone, and the magnitude of each source 'A' is given by 1n/M^2. calculate the pressure as a function of the angle between the reciever and the dipole for a reciever 10 m from the dipole...

Hi, currently i am studying the performance of axial turbocharger, and i have formulate the equation and all the data in Microsoft excel, and i want it to be convert into C++ language, could anyone teach me how to start by doing this, because i am totally new in C++...please...i already upload...

Consider a situation in which two motorists, Arwa and Bao, share the same driving route but own different sized vehicles. Arwa fills up her vehicle’s tank at a station along her normal route for US$ p(1) per litre. On the other hand, Bao drives an extra d kilometres out of his normal route to...

HI, i am a student taking final year project in my university, my project title was C++ modelling of axial turbocharger, it was a counter-rotating turbocharger, can anyone help me to get some useful information to complete my project? thanks

Hi all, I´m a researcher in computational biology thinking on topics quite far from my field. Would you help me? Thanks in advance! I want to calculate the drag force in air of big rigid spherical and cylindrical objects at speeds form 0 to 100 Km/h. Their diameter would range from 1 to 20m...

Hello. I am currently a student at UCF in Orlando, FL. Simulation and modelling are big things around here. I have the opportunity to get my master's degree paid for by the lab I work in. I'm not terribly excited to stay here for another two years, but I really don't want to get a master's if I...

Hi all. I am working on a problem in which I want to model the collision of a moving object, with mass m1, with a stationary base. I have calculated the velocity of the moving object at the instant of collision. I want to model this collision using a mass spring system with damping. My...

Homework Statement A culture of bacteria have a growth rate (as a percent) given by kb per year, constant k>0 and b is the number of bacteria. A virus removes bacteria at a rate of m bacteria per year. I am trying to model this information using an ODE, but might be making a mistake. Homework...

Homework Statement Model the pupil of the eye using a single slit. If the eye is able to notice changes in intensity of 20% show that it can distinguish two objects separated by an angle of 0.00015 radians if =500nm and diameter=4mm. Homework Equations I=Iosin^2((π/λ)asinθ)/...

Hi This isn't a homework question, just a problem I thought up of but would require some implementation I don't really know how to do. Homework Statement If I have a microfluidic channel with laminar flow and a parabolic velocity profile as predicted in the Hagen-Poiseuille flow, and I...

I'm looking for a good resource about modelling for differential equations. I've completed two courses on ODE's and PDE's, but they both lacked in the applications/modelling department. Can anyone recommend a good resource/book on modelling?

Hey there, I am currently working on creating models in Abaqus of Wrist implants to see how they respond under different loading conditions. I have used Mimics to export orphan meshes of the wrist bones and also imported the wrist implant itself. My simulations seems to be running fine all...

Firstly, this is not homework - it's a project I have started our of sheer curiosity. I have searched quite at length, but cannot really find anything that suits my problem. I want to model this on a computer and would like to implement it myself as I would like to understand the...

say i have 500,000 0s or 1s. say i have 50 such sets, each that i have ranked or assigned a value to - "harshness". can i then extrapolate - is that the right word - to find the perfect dataset that instantiates the property of harshness? and can i measure the harshness of other datasets...

Hello friends, I am into modelling of electric hot water tank which is vertical and has the capacity of 120 litres. I just assumed certain charactersitics of an existing heater so as to be more realistic in my approach. Now I am facing certain troubles in my calculations, if you know please...

I'm looking for a general model that I can use to approximate the evaporation rate of a small pool of liquid. The purpose is to calculate the rate at which a few mL of liquid is evaporating at the bottom of a cylindrical test chamber for an experiment. I figured that I wouldn't have any trouble...

Hi, I'm new to MATLAB and programming, but I hoping to find out if I can have a variables in my program take on certain values only for certain time intervals. For example, I am using ode23s to solve some equations for me, but for the time interval [0,10] I would like one of the variables...

Hi, hopefully this is a simple question and easily answered. I've been doing some reading on the subject of mathematical modelling and examples of modelling reports. In one report, the failings of the model are put down to "dynamic forces". I've taken this to mean that there are external...

Dear all! I have encountered a problem with modelling a truss. When modelling on an analysis software, you must release the ends of the joints, but not all or it will form a mechanism, therefore you release all but one of the joint. But what I have here, is a truss that is released on all ends...

I am pursuing bachelor in engineering.i have a case study involving the stabilization of an inverted pendulum about it's unstable equilibrium point. My problem is that I have to digitalize my system before i can implement it. Can anyone tell me how to digitalize the system.

http://dl.dropbox.com/u/33103477/Resistor.png For the first bit first I solved the equation \frac{dI}{dt}=\frac{U-RI}{L} I(t)=\frac{U-C_2e^{\frac{-t}{L}}}{R} Now I put in T(0)=0 to work out the constant and I got I(t)=\frac{U-Ue^{\frac{-t}{L}}}{R} Now here's the dodgy bit, I did...

A certain smoker has a daily intake of 0.02 milligrams of nicotine. It is assumed that 1% of nicotine is disintegrated by the body per day. (i) Set up a diference equation for the amount of nicotine N_t after t days, starting with an initial level of N_0 = 0. (ii) Derive a closed form...

Wasn't really sure where to post this - it's not much of a problem - rather hoping for some suggestions on an essay topic: I'm required to write a short essay (in the style of a wikipedia article, 1500-2000 words) for a 'Modelling Complex Systems' module; I've been given the following...

Hello PF, I am in a bind and wonder if anyone has any advise. Finishing my undergraduate learning I applied for numerous PhD positions, and was incredibly lucky to receive the following offers 1) Modelling of complex systems specializing in magnetic materials (condensed matter...

Homework Statement Suppose a book of 600 pages contains a total of 240 typographical errors. Develop a poisson approximation for the probability that three partiular successive pages are error-free. The Attempt at a Solution I say that the number of errors is poissondistributed...

Homework Statement The Attempt at a Solution I think that problems such as this one tend to take on the rough form of \frac{dQ}{dt} = rate in - rate out. I suppose I should treat each lake such that is has it's own equation regarding concentration. I reasoned that, in the case of the...

Hi guys, What I am trying to do is to create a mathematical model for the attraction forces between two or more electromagnets placed parallel to each other. (when the exitation currents are static) And for this i thought the best approach would be to have a model that can provide a 3D model...

I would like to do the mathmatical modelling then apply it in matlab. This is my trailier. Vp-ip*Rp-Lp*(dip/dt)-Rc*ic = 0 ----- 1 Vp-Lm*(dim/dt) = 0 ------2 i need the modelling of the secondary voltage to the primary and the flux Vs= ? flux= ? I did apply it in MATLAB but didn't work.

Homework Statement Working on a project for a vibrations course, task is to quantitatively analyse a system in which mechanical vibrations occur. I chose to model aircraft landing gear, for a variety of different airplanes, namely one large transport (747), a simple tricycle gear GA plane...

Hey all. I feel as if I've dug myself into a dead end and I'd appreciate some career advice. I'm a senior computer engineering student with a 3.8 GPA at a decent engineering school. I chose the major to further understand the mysteries of computers. I enjoyed learning what I did, because now I...

Please excuse me if this is not the most appropriate subforum for this question and please move it if necessary. I am trying to make a numerical model with Mathematica to synthesize the sound of a struck drum head (circular membrane). I solve the wave equation for a circular membrane to get a...

Hi Could anyone point me in the right direction? I'm employed at a small firm, only three employees at the time being. Our competencies spans from architecture to programming. We're in need of somebody who can help us create a finite element solution which we can implement in the cad...

Hi all, I am attempting to model soliton formation numerically. The solitons will be formed by moving a body of some sort through a shallow channel of water with the free surface subject to atmospheric pressure. My goal would be to numerically predict wave amplitudes, wavelengths...

Hi guys, me and my fellow classmate have been working on a math problem we believe to be a Modeling and Optimization type problem in our calculus class. We've been at it for 2 days now! Just can't seem to figure it out... We'd really like appreciate and all help! Homework Statement [There is...

Dyalog APL anyone? Anyone? Anyone? I've been trying to find resources on modelling specific physics situations with Dyalog APL and have had no luck. I have Mastering Dyalog APL which is the guide from their website but I want some more information. I'm looking to model specifically forced and...

Homework Statement Please see the picture shown below: Homework Equations I know the inertias of the AO and BO beams w/ respect to O are both 1/3*ml^2, but what are the inertias of AC and BC w/ respect to O?The Attempt at a Solution Any other hints that you guys have for solving a problem like...

How can we merge 3 FFT spectrum graphs in one as shown in the picture? AND THANK YOU I have written the codes for the 3 spectrums but need to join them as shown.