Recent content by c.teixeira

Forgot to thank you at the time. Your answer was helpful.

Hi there, I am trying to solve a structural mechanics problem. I am doing so by two methods. On one hand, I am using a F.E.A software (ANSYS) to get me the solutions. At the same time I am solving the problem analytically. The issue is that ANSYS is solving the problem using a diferent theory...

The radius is 0.008[m]. It is a regular hexagon. The analysis runs all the way. And pretty fast too.(except for the last mesh)

Hi, I am trying to model a simple plane stress problem using Ansys. I am using Ansys 14.0. The problem is a simple square plate, without a corner, and with a hexagon hole around the midle. The boundary conditions consist of a constant pressure on the top side, and full constrain on the...

Hi there. I am designing a type cilindrical can full of a fluid, with a temperature difference between the top and bottom. Now, after the simulation of the free convection phenomenom in COMSOL, I wanted to understand the effect of varying the temperatures, to the "fluid movement" (fluid...

Ok, I undestood your explanation. It makes sense. It is much like the explanation I tough to myself. Thank you,

thank you for your answer bigfooted, However, I have a hard time agreeing with that explanation. \frac{\partial(κ\frac{\partial T}{\partial x})}{\partial x} + \frac{\partial(κ\frac{\partialτ}{\partial y})}{\partial y} + \frac{\partial(κ\frac{\partial T}{\partial z})}{\partial z} + \dot{q}...

Hi there. At first I tought of posting this thread on the homework category, but this is a conceptual doubt rather than anything else. While revisiting Heat Transfer I stumbled upon a simple problem, that yet got me thinking. It is as follows: Before anything else, let me show...

Hi there! I always think whether I am posting this correctly, or this belongs to the homework section. If so, my apologies. I am trying to understand the solutions for a problem in Spicak Calculus, 3^{rd} edition. #8-13 The Problem: "Let A and B bt two nonempty sets of numbers...

Let: f(x) = 3x^{2}; g(x) = 2x; \int[3x^{2} + 2x] dx = x^{3} +x^{2} + C_{1}, \int3x^{2}dx = x^{3} + C_{2}, \int2xdx = x^{2} + C_{3} Then, \int[3x^{2} + 2x] dx = \int3x^{2}dx + \int2xdx only if C_{1} = C_{2} + C _{3}, right? So how exacltly do you prove that? Using pwsnafu advice?

So, my little "proof", is correct, and "rigorously" we should have \int[f(x)+g(x)]dx = \int f(x)dx + \int g(x)dx + C? Altough, the Constant C doesn't do any difference as a consequece to definite integrals. So, I can think that Spivak didn't write the C, because of this non-consequece to...

Also, I believe that making A(x) + K_{A} = \int[f(x)+g(x)]dx, and then showing that K_{A} = K_{B} + K_{C}, is the same thing as defining A(x) = \int[f(x)+g(x)]dx, and then showing that K = 0. Spivak says that concer for this Constants is merely an annoyance, but not knowing exactly why...

So, how can I prove that? And why would I want to show that? (##k_A = k_B + k_C##) I don't understand. If my explnation is correct, and K is generally not 0, as you said, wouldn't that make \int[f(x) + g(x) dx = \int f(x)dx + \int g(x)dx + K instead? What I undersandt from the above...

Hi there! If one would want to prove that the indefined integral : \int[f(x)+g(x)]dx = \int f(x)dx + \int g(x)dx. Would this be apropriate: A(x) = \int[f(x)+g(x)]dx; B(x) = \int f(x)dx; C(x) = \int g(x)dx. And since the primitive of a fuction is another fuction whose derivative...

Thanks!