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0 votes
1 answer
44 views

The differential equation of the change of the amount of the nutrition inside of the incubator. [closed]

The problem statement is as below. We will handle the incubator with the microbes inside of it. The microbe increases consuming a nutrition. The amount of the nutrition is never increased. $10^3*P(t):=...
user avatar
0 votes
1 answer
36 views

Finding out the transer function where the equation of the input function and the output function are given

$G(s):=$The transfer function which I want to find out. $f(t):=$The input function of some system. $x(t):=$The output function of some system. The below equation being given. $4\frac{dx(t)}{dt}+3x(t)=...
user avatar
1 vote
0 answers
45 views

Conceptual complex dynamics - Is it reasonable to perform bifurcation diagrams on PDE's?

I am working on a PDE model, the subject has been modeled with ODE's before. The articles usually have a bifurcation diagram, and to be able to validate my model, I want to compare my work with the ...
confused's user avatar
1 vote
1 answer
210 views

Criterion to see if you can neglect air drag in projectile motion

In physics education you often consider "real world problems" with projectile motion. Most times in introductory courses you neglect air drag. But how can students (knowing nothing about ...
Julia's user avatar
  • 987
0 votes
0 answers
92 views

Derive the equations of motion and determine whether angular momentum is conserved..

Suppose that the gravitational force is not given by the inverse-square law, and instead is $$ F_{grav}=\left(\frac{A}{r^{2}}+\frac{B}{r^{4}}\right)\hat{r}, $$ where A and B are real constants. Derive ...
rani's user avatar
  • 1
1 vote
0 answers
46 views

Differential equation undamped system

Question image How can I solve this question? An object weighting 8 pounds is suspended from a spring stretching it 0.5 feet. The weight, which is at rest in the equilibrium position, is struck an ...
Semih Ataman's user avatar
0 votes
0 answers
64 views

Differential Equation Application of Physics-Sliding Block

Where I can I start to solve this question? A block is released with an initial velocity v0 = 20 m/s from the bottom of an inclined plane making an angle of 30◦ with the horizontal. If the constant ...
Semih Ataman's user avatar
1 vote
1 answer
145 views

Basic ODE story - tank with pumps

Full tank has $500$ liter of water containing $0.2\%$ of salt. One pipe pumps clear water in ($100$ liters per minute) and the other gets the mixture from the tank ($100$ liters per minute too). ...
blahblah's user avatar
  • 2,190
-1 votes
1 answer
103 views

Calculating if Romeo and Juliet will stay together always or not. [closed]

I have two equations which describe the Love of Romeo for Juliet (R) and Love of Juliet for Romeo (J) as a function of time, $t$. $R=-c_1e^{3t}-c_2e^{2t}$ $J=2c_1e^{3t}+c_2e^{2t}$ They will stay ...
Srijan's user avatar
  • 25
1 vote
1 answer
39 views

perfect lens: expression for interface

Suppose I want to find a function $(x,z) \mapsto y((x^2+z^2)^{1/2})$ which must represent the interface between two translucent media with different refractive index and which must yield a perfect ...
5th decile's user avatar
  • 2,455
0 votes
2 answers
3k views

Applications of the Laplace Transform

I am curious to know what kind of applications the Laplace transform has. Yes, I know people will reference Wikipedia, and other online sites which discuss the Laplace transform at length. However, ...
Nicolas Bourbaki's user avatar
1 vote
1 answer
87 views

Approximation for Lambert W containing exponential, to help simplify ODE

I have a linear ODE derived from electrical engineering of the form: $$\omega\cos(\omega t) - W\left(\frac{e^{\omega\cos(\omega t)}}{C}\right) = \frac{Ai'(t)}{i(t)}$$ Where A, C are constants, and W ...
MattyZ's user avatar
  • 2,323
1 vote
1 answer
46 views

Which logistic equation is better for solving this question?

So I was given a question about spread of disease: A virus is spreading through a city of 50,000 people who take no precautions. The virus was brought to the town by 100 people and it was found ...
Tan Qiyan's user avatar
1 vote
1 answer
444 views

Applications of coupled systems of $\;2\times 2\;$ linear differential equations

I am providing maths help to some students studying just before University level in mathematics. I am writing some practice questions for them on solving coupled first order linear equations and I ...
PhysicsMathsLove's user avatar
0 votes
1 answer
211 views

Solutions of the Falkner Skan Equation for Negative Beta

I was wondering what the solution to the Falkner Skan equation, $$f^{\prime\prime\prime}+ff^{\prime\prime}+\beta(1-f^{\prime 2})=0$$ looks like for negative values of $\beta$ and whether solutions for ...
user516948's user avatar

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