Recent content by springo

Only how to find speed and acceleration of the elements of the mechanism, that is applying Newton's laws to solve kinematics (and dynamics) problems graphically.

Hi, I would like to know if there's anywhere I can find information on how to solve problems that deal with mechanisms (1 degree of freedom) using graphical methods, because I couldn't find any. Thank you.

Homework Statement Find the Fourier series for ex for x in (-1,1). Find the Parseval identity. Homework Equations The Attempt at a Solution c_{n}=\frac{1}{2}\int_{-1}^{1}e^{x}e^{-i n x}dx Where cn are the coefficients of the Fourier series. I tried plotting \sum_{k=-\infty}^{\infty}c_{n}e^{i...

Sunday bump... :)

Homework Statement How do you find the tensor of inertia for fractions of the usual volumes? (like half of a sphere, half of a cylinder, half of a disk, quarter of a disk, etc.) I already know the tensor of inertia for the whole volume. Take M as the fraction of the volume's mass, not the...

Homework Statement t y'' + (3 t-1) y' + 3 y = 6 e^{-3t} y(0) = 1 y(5) = 2 Homework Equations The Attempt at a Solution I tried applying the Laplace transform to the equation but I was having a little trouble... L [t·y''] = -dL[y'']/ds = s2·Y' + 2·s·Y - y(0) = s2·Y' + 2·s·Y - 1 L...

Thanks. OK, so assuming my "attempt at a solution" tensor was right, I get to the following tensor: \begin{bmatrix} \frac{MR^{2}}{2} & 0 & 0 \\ 0 & \frac{MR^{2}}{4} & 0 \\ 0 & 0 & \frac{MR^{2}}{2} \end{bmatrix} +\begin{bmatrix} 0 & 0 & 0 \\ 0 & MR^{2} & 0 \\ 0 & 0 & MR^{2} \end{bmatrix}...

Homework Statement Find the tensor of inertia for a half disk with mass M and then use that to get the angular momentum along the axis in the figure. http://img138.imageshack.us/img138/5312/problemr.png Homework Equations Moment of inertia for the whole disk (with mass 2M)...

Bump for help :)

Hey, So I have a few questions because I don't understand some of the theory behind magnetism in matter. First, I have studied electric fields in matter and it seems logical that dielectrics get attracted to regions with higher field, because they're polarized and this creates the usual...

The thing is I was taking for the first column of P, an eigenvector of M. For the second one, a vector that is the nullspace of (M+3I)2 but is not an eigenvector of M. For the third one, a vector that is in the nullspace of (M+3I)3 (which is R3) but not in the eigenspace of (M+3I)2. Isn't that a...

J is the Jordan normal form of M and P is the matrix so that P·J·P-1 = M.

Bump for help! :)

Hey, I'm going to use this thread, because I was checking it out (studying differential equations too) and I didn't quite understand what he did in the beginning, how James got to those 2 equations about y and y'. The way I would have done this is set p = y', therefore p' = dp/dx = p·dp/dy and...

Thanks for your replies! Oh, this is bad. I was using Mathematica for my calculations, it turns out using 2 doesn't do a real matrix multiplication, it does a dot product or something similar. My bad... Now I took as eigenvectors: - (M + 3I)2 : [ 1 , 0 , 1 ] - (M + 3I)3 : [ 0 , 0 , 1 ] So...