Recent content by ryukyu

Thanks for the replies thus far. @tiny-tim: No I am not aiming to teach them about work and energy, but I do like to back my demonstrations with math when I make claims like "this takes less work than this.." especially when parents start asking questions. @Godianus: I'm not making the...

I am going to be doing a demonstration of Archimedes' wheel for some 6-9 year-old students and would like to try to figure out the work done by the wheel to lift 10 liters of water 1m vs the lifting of a 10 liter pale the same height. Anyone know of a way to easily figure the work done in...

Homework Statement Calculate the first three energy leveles for an electron in a quantum well of width 10Angstrom and infinite walls. Homework Equations En=\frac{n2pi2(hbar)2}{2mL2} The Attempt at a Solution m=9.109E-31Kg L=10E-10m hbar=1.055E-34 En=n2*6.032E-20 My problem...

Thanks, I knew it was something simple that I had missed.

Homework Statement Point A is at an electrostatic potential of +1V relative to point B in a vacuum. An electron initially at rest at B moves to A. What is its velocity in m/s? Homework Equations E = PE + KE PE= J/q * q KE = 0.5 mv^2 (where v = velocity) The Attempt at a Solution...

I apologize for not saying thanks again. I do find this site a valuable resource in attempting to learn this material instead of just blindly using equations and hoping that things work out.

A 1mm-diameter copper wire is shaped into a square loop of side = 4cm. It is placed in a plane normal to a magnetic field increasing with time as \vec{B}=1t\hat{z}Wb/m2. Calculate the magnetic flux density at the center of the loop. I found that the magnitude of the induced current is...

Thanks for the response and the insight. So for the top of said cube I would integrate the z-hat coefficient by dydx? the bottom by z-hat (-dydx) the right by y-hat (dxdz) left by y-hat(-dxdz) front by x-hat(dydz) and back x-hat(-dydz)...

Thanks again. I have been working on the homework for this class for at least 30 hours on and off and it's only 7 problems. The professor's method of instruction and my method of learning just don't blend well and that's not his fault, I just need to learn a new way to learn.

Homework Statement For the given flux density: \vec{D}=(2y2+z)\widehat{x}+(4xy)\widehat{y}^+(xz)\widehat{z} a)Determine the charge density. b)Find the total charge enclosed if the surface is 0<x<1, 0<y<1, 0<z<1 (unit cube) c)Confirm Gauss’s law by finding the net flux through the surface of...

I've got it straightened out now. I was assuming eps0 was unitless. But even given that enlightenment, are these really mega-Webers that seems even more out of scale?

Thanks for the quick response. The whole mega-Coulomb just had me worried.

Homework Statement Three concentric spherical shells ,r=1m ,r=2m and r=3m, respectively, have charge distributions 2, −4, and 5 μC/m2. Calculate the flux through r=1.5m and r=2.5m Homework Equations Since we are talking about Gaussian surfaces I assume that the flux at 1.5m is...

Great! This gets me a bit further. Now I am just a bit confused about expressing my answer. I did the partial fraction expansion and got a=(1/4) and b=(-1/4) This gave me: H(s)=(1/4)(1/s) - (1/4)(1/(s+4)) taking the Laplace Inverse h(t) = (1/4)u(t) - (1/4)e^(-4t)u(t) While in...

1. Find the impulse response h(t) given: z'(t) + 4z(t) = 4x(t) 2. The attempt at a solution I first decided to divide through by 4 (1/4)z'(t) + z(t) = x(t) since we are looking for impulse response I made the following substitutions: let z(t) = h(t) let x(t) = dirac(t)...