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2 votes
0 answers
76 views

whats is the applications of the minimization of eigenvalue in the real life ( physics,the natural sciences...)

let $\lambda_{1}(\Omega),\lambda{2}(\Omega),\lambda_{3}(\Omega)...$ the eigenvlues of the laplacian Operator with Dirichlet condition on the boundary on $\Omega $ the classical spectrale optimisation ...
Bernstein's user avatar
  • 704
1 vote
0 answers
117 views

Physical meaning of this boundary value differential equation

I am considering the following boundary value problem: $$-\frac{\mathrm{d}}{\mathrm{d}x} \left[ a(x) \frac{\mathrm{d}}{\mathrm{d}x}(u(x)) \right] + c(x)u(x) = f(x),$$ where $x \in [0,1]$ and $u(0) = ...
Tomas Jorovic's user avatar
9 votes
1 answer
132 views

How many times do you have go back and forth to get out of a deadlock?

Here's a challenging question for you math lovers. This question was originally asked in Physics SE but I was suggested to post it here.( You can see it here.) Many a times we have been inside a ...
user avatar
2 votes
2 answers
252 views

Probability density for velocity in mechanical energy

To be sure my basic physics isn't rusty... Consider a 2-D bowled shaped classical potential well within which a classical particle of mass m is rolling. In this system the conservation of energy ...
Mathematicing's user avatar
2 votes
2 answers
1k views

Prove $v = \sqrt{\frac{2gRh}{R + h}}$ from Given (below)

Given: $$F = \frac{mgR^2}{(x + R)^2}$$ $m = \text{mass}$ $g = \text{Acceleration due to gravity}$ $x = x(t)$ is the object's distance above the surface at time $t$. I believe this is the ...
Ikechukwu Anude's user avatar
1 vote
1 answer
7k views

Hydrostatic force problem with trapezoids?

If I have a trapezoid with a $4$m and $8$m base that is partly submerged vertically in water so that the top is $2$m above the surface and the bottom is $2$m below the surface; how do I express the ...
Computer's user avatar
  • 575
0 votes
1 answer
4k views

UNRESOLVED: Pushing oil out of a tank using work integration

I have a tank of oil with a density of $900\frac{kg}{m^3}$. My tank has a spout that is $2$ meters tall and the general radius of the tank is $6$ meters. It is half full of oil and I want to find the ...
Computer's user avatar
  • 575
0 votes
1 answer
112 views

How to show something does not vary with time?

Consider a glider flying at velocity $\bf u$ (giving $u = |\bf u| $ on its speedometer) at an angle $θ ∈ (−π, π]$ to the horizon. Positive angle $θ ∈ (0, π/2)$ coincides with the glider’s nose ...
Ryan J's user avatar
  • 145
0 votes
2 answers
1k views

Tacoma Narrows bridge collapse : mathematical explanation. [closed]

What is the exact mathematical reason behind the Tacoma narrow bridge collapse ? I have googled about the collapse , but I didn't get a correct reason and a mathematical model.
user100749's user avatar
6 votes
1 answer
2k views

Applications of group theory to classical mechanics

Today, a friend and I solved a classical mechanics problem using group theory. The problem was the following: Around a circumference, there are $N$ children evenly spaced. In the center, there is a ...
Henrique Augusto Souza's user avatar
8 votes
1 answer
360 views

How can one tell if a PDE describes wave behaviour?

I have been looking at a lot of different non-linear PDEs which describe waves lately and have come to the realisation that I don't know what it is about these PDEs that make them behave like waves. ...
swalsh1123's user avatar
1 vote
0 answers
80 views

Heat problem with an internal source of heat for which the maximum principle doesn't hold.

Heat problem with an internal source of heat for which the maximum principle doesn't hold. The problem is the following and honestly I don't know how to solve it... $$u_{t}=u_{tt}+2(t+1)+x(1-x) , 0&...
Rosa Maria Gtz.'s user avatar
3 votes
1 answer
5k views

Applied Mathematics: Spherical Polar Coordinates and Newton's Second Law

I've been attempting this question but can't seem to find a solution. Question: A particle of mass $m$ moves under the influence of a force which, in spherical polar coordinates, only acts in the ...
Geometry's user avatar
  • 455
0 votes
1 answer
46 views

Locus Equation $f(r) = \frac{-h^2}{r^3}$?

For the Locus equation $$\frac{\mathrm{d^2}u }{\mathrm{d} \theta^2} + u = - \frac{1}{h^2u^2}f\left(\frac{1}{u} \right )$$ How do I find the solution for $f(r)= \frac{-h^2}{r^3}$ and sketch the ...
Geometry's user avatar
  • 455
1 vote
1 answer
224 views

When is $0$ ever used in real life?

I've just been going through an equation, which is as follows: $(x+4)^2 = 16$ Lets work through it: $$x^2 + 8x +16 = 16$$ $$x^2 +8x = 0$$ $$x^2 = -8x$$ $$x = -8$$ However, as i've just found ...
user2901512's user avatar
  • 2,110

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