Recent content by samee

Ok, I've been working on this and am still confused. I think that I'm missing some key information at a very basic level and that's what's killing me. So basically, I'm modeling the mechanical performance of a material in terms of it's elastic and shear response in relation to it's porosity. I...

My work is only the model. I'm comparing the model to a set of published data from another research group. Aside from reading the paper, I really have no idea how they did their experiment. What I mean is, they didn't publish any error analysis for their data points, so I don't know what to do...

Hi everyone. I'm a graduate student and am struggling with something that may possibly be trivial. So, my research is creating a mathematical model to represent a real system. I have data points from my real system that I want to compare my model to. How do I do a regression analysis and get...

Okay, I'm looking more carefully through my book, and I found a problem with a temperature difference on a thin disk. They simplify the problem and explain, "since u does not vary with θ, we dropped the uθθ term and solved the reduced equation. If you have doubts about this step, observe that...

alpha2(X"/X+Y"/Y)=T'/T X"/X+Y"/Y=T'/(Talpha2)=λ=0 If I were just doing X"/X=T'/(Talpha2), I would use separation of variables method to solve and get that X(x)=ax+b and T(t)=c Since this is not just X"/X, but X"/X+Y"/Y, I don't think I know how to solve the problem.

I'm confused because this was supposed to be solved with separation of variables. I don't know how to do that with 3 variables.

I was just guessing. Since u(x,t)=X(x)T(t), I assumed that U(x,y,t)=[X(x)+Y(y)]T(t) because x and y are vectors and T isn't. And yes, I meant X"/X, not X'''/X

Okay, so I'm going to expand the formula from alpha2uxx to alpha2(uxx+uyy)=ut Then, u(x,y,t)=(X(x)+Y(y))T(t) and X'"X+Y"/Y=T'/alpha2T=λ and λ=0 so, X(x)=ax+b, Y(y)=cy+d and T(t)=e Then u(x,y,t)=c(ax+cy+b+d) right?

Homework Statement The edges of a thin plate are held at the temperature described below. Determine the steady-state temperature distribution in the plate. Assume the large flat surfaces to be insulated. If the plate is lying along the x-y plane, then one corner would be at the origin...

Homework Statement A long copper rod with insulated lateral surface has its left end maintained at a temperature of 0C and its right end, at x=2m , maintained at 100C . Determine the temperature T as a function of time and coordinate if the initial condition is given by T(x,0)={ 100x, 0<x<1...

Ah! No wait, there's more! I know what I'm doing now, silly me. I set x' and y' to zero and solve for the points. x'=0, ∴x=0 y'=0, -cosy=0, ∴y=(1/2)(2n+1)pi So I have infinite points along the y-axis. I used http://www.math.rutgers.edu/courses/ODE/sherod/phase-local.html to...

Okay, so I check them out by computing the dot product of F over each surface?

Thank you so much! I took an incomplete due to family issues in this class and I'm trying to make it up this summer, but it's been such a mess trying to remember the 1st half of the class and do homework for the 2nd half with almost a year between. Thank you for your help!

OK! So (∂f/∂x)=(∂/∂x)sinh(yz)=0 and (∂h/∂z)=(∂/∂z)y4=0 so the divergence of F is zero! and anything dot zero is zero, right? so the answer is zero??

Okay, so for my problem I have x=y' x'=y" so I substitute and x'+cosy=0 x'=-cosy so my system of equations is; y'=x x'=-cosy right? Then I just solve like it's a system of equations and look for the singularities as the critical points?