Recent content by _F_

My favorite math books: 1. Linear Algebra by Friedberg, Insel, and Spence. 2. Principals of Mathematical Reasoning by Peter J. Eccles. (if you need to learn proofs, this book is the way to go). 3. Set Theory and Logic by Robert Stoll. 4. Handbook of Mathematics by Bronshtien, Semendyayev...

I'm not trying to argue that you can use electromagnetic waves to harness any type of perpetual motion. I was just asking if an elecromagnetic wave is a type (maybe "type" is the wrong word here?) of perpetual motion? Or maybe I'm mistaken. Do electromagnetic waves die out over some distance...

why not? okay. Thank you.

I have read about interstellar "sailing ships" that rely on radiation presuure. My question is not really technical, just something to mull over. But I figure that if we set a sailing spacecraft from earth, I don't think it will be able to get to another solar system. Sailing ships use...

Hi all, Can someone please elaborate on some of the following ideas so that I can get these down correctly? 1. is an electromagnetic wave a form of a self-perpetual motion machine? 2. since electric and magnetic fields contain energy, is this the hope that people (Tesla!) have for...

You're right. But that said, if you take away the zero's you still get a 1x3 matrix whose dimension is 3...

Homework Statement Find the nullity of the linear transformation T:M_2x3(F) -> M_2x2(F) defined by: T([a11, a12, a13; a21, a22, a23]) = ([2*a11 - a12, a13 + 2*a12; 0, 0]) The Attempt at a Solution N(T) = {x in M_2x3(F) | T(x) = 0} 2*a11 - a12 = 0 => a11 = (a12)/2...

Can anyone point me in the right direction here? I still can't wrap my head around this. :(If the charge density is p = q/volume. Then p = (14*10^-6 C)/(4/3*pi*(.25m)^2 = 2.14*10^-4 C/m^3 But how do I use this?

I would say Q/A = 14*10^-6 C * .2827 m^2 = 5*10^-5 C/m^2 But plugging that into: E = (5*10^-5 C/m^2)/e_0 = 5.59*10^6 N/C. But my book says E = 1.21 MN/C

I know its not 14uC. It must be something else, but I can't seem to figure out what. Q = (e_0)*E*A ? A = 4(pi)r^2 = 4(pi)(.15m)^2 = .2827m^2 ?

Yes I am familiar with Gauss's Law. flux = integral(EAcos(theta)) = q_enclosed/e_0. I'm still not sure where to go from here, though.

Homework Statement A solid sphere 25cm in radius carries 14uC, distributed uniformly throughout its volume. Find the electric field strength (a.) 15cm, (b.) 25cm, (c.) 50cm from the sphere's center. R = .25m Q = 14 * 10^-6 C Homework Equations p = q/(volume) E = (kq)/r^2 The...

Ack! Thanks. Such a stupid mistake. :rolleyes:

J = kg*m^2/s^2 V = [J/C] Vq = [J] K = [J] v^2 = 2K/m = [m^2/s^2] v = [m/s] Where did I go wrong?

Okay, so K = (1/2)mv^2 We have volts in J/C, so to get a value of just energy would we multiply V*q? If so: V*q = (2.5*10^3 J/C)(1.6*10^-19 C) = 4*10^-16 J. So K = 4*10^-16 J, Then K/[(1/2)m] = v^2 => (4*10^-16 J)/[(1/2)(9.1*10^-31 kg) = 8.79*10^14 J/kg So v^2 = 8.79*10^14 J/kg...