Recent content by brentd49

Hi, I was wondering if there were other people out there that used Tablet PCs, specifically students. I only know of one other person who uses one, but he doesn't use it for class because of battery life. I am considering buying one, but I'd like to hear from other students that have...

I see. So, one must consider the change in potential relative to where it starts and where it ends. Does this mean that electric potential energy must always be written \Delta U never U_f, U_i?

I have a very basic question. An electron is accelerated through a potential V, what is the velocity? Obviously, this can be solved using conservation of mechanical energy, but why am I off by a negative? K_i + U_i = K_f + U_f 0 + (-qV) = \frac{1}{2} m v^2 + 0 v = \sqrt{-2qV/m} My...

anyone.............

so, if I take my orgin at the far left, with l_o the natural length. x = l_f - l_o x = \sqrt{a^2 + d^2} - l_o so, now I need to replace d, right? d = \sqrt{(l_o + x)^2 - a^2} but that can't be right, because I would have x = x(x) . I must be missing something.

^bump .......

I know there has to be a program better than Microsoft Word. When I try to move images/graphs around in MS Word they jump around all over the place. I end up having to reformat a paper 20 times because everytime I add a image, it effects the whole paper. Or if MS Word is popular how do you...

I will make a crude visualization of this system: |-------------O--------------| <-----a------><------a------> Identical springs: k1=k2=k Natural Length: l > a The problem is to prove that the system is unstable. Obviously, a slight movement directed off the horizontal axis will cause the...

Maybe you could focus on one topic. I'm a bit curious how they can get the ball to bend so much on free kicks, i.e. around human walls. One would be tempted to say rotational kinetic energy, but if it is a knuckle ball (no spinning) how is it bending? This is true for baseball as well.

There seems to be two different uses of potential difference that either contradict each other, or at the very least make it very confusing. Let me write the three different forms: Definition: Vf-Vi= -E*d Differential: dV=-E*dr (Vi=0) Point Charge: V=E*r (Vf=0) What is with the different...

You could take a practice test on the general and subject to see where you stand and what areas you need to work on. I would say, in general, for the general test to spend about three weeks to learn some vocabulary and math tricks. For the subject test, I would say that two months is plenty if...

I looked at the links, but I'm still having a little trouble.. (1) There seems to be an inconsistency when applying Gauss's Law. When they calculate the electric field between two insulated sheets they use superposition to find the net electric field. But for two conducting sheets, the...

I understand now, thanks. I think Halliday, Resnik could have done a better job, though.

^bump I must have some concept wrong, because they use that equation again for the conductor when they are caculating the electric field inside a conductor with a dielectric, i.e. E=qf/2eA+qf/2eA-qi/2eA-qi/2ea (where qf=free charge on conducting plate, and qi=charge bound to dielectric). I...

How does one prove that the force between two conductor plates is F=q^2/2eA, where e=epsilon. If I use F=qE. Where the electric field is generated by one of the conducting plates: E=q/eA, then F=q^2/eA. I think what the answer assumes is that the E-field is from a uniform plate...