Recent content by E&M

at this point, i think i can ignore v. dv/dx and simply write a = dv/dt. I integrated after that which gave me an expression for v. v = -gt - g/(vt)2 \intv2dt b/c terminal velocity is a constant, i pulled it out of the integral.

oh yeah my bad. It's v_dot, or acceleration.

Homework Statement Given that a = -g[1+(v/vt)2] where, v = velocity of an object vt = terminal velocity find x(v) Homework Equations v = dx/dt The Attempt at a Solution i started from a = dv/dt = dv/dx . dx/dt. but could not go to x(v)

Homework Statement \Psi(x,0) = A[\psi1 + \psi2 + \psi3] How long will \Psi(x,t) take to go back to \Psi(x,0) ? E1, E2, E3 are the energies associated with each \psi1, \psi2, \psi3. Homework Equations TISE The Attempt at a Solution I multiplied \Psi(x,0) by e-iEnt/h...

Thank you both for your responses. I am not trying to get into applied Physics program, so I have to submit PGRE score anyway. I am not completely concerned about the school's prestige but usually prestigious schools tend to have good researches and faculties. I will apply to some top schools...

so \inte-ikx \delta (x - a) = e-ika ?

1/\sqrt{2\pi}\int\delta(x+\alpha)e-ikx + \delta(x-\alpha)e-ikx dx I tried to integrate those terms by parts (uv substitution). \int\delta(x+\alpha) = 1. Isn't that right ? Also I think f(x)\int\delta(x+\alpha) = f(\alpha). Am i right ?

Homework Statement I am really confused in my electrodynamics class. I have the following function. f(x) = \delta (x + \alpha ) + \delta(x -\alpha) How do i convert this into Fourier Tranform ? Those are dirac delta functions on either sides of the origin. Homework Equations...

Hi, I am an international student studying in US. I have a Physics GPA of 4.0 and cumulative GPA of ~ 3.9. I recently took a PGRE and haven't obtained my scores yet. I am guessing that I should get a score of about 650 or so. I have pretty good research experiences in reputed places. I have...

Homework Statement There are two rotating disks which rotate with angular velocity omega in the same direction about a z axis. Will the magnetic field at the center of those two disks cancel out or will it be twice the field due to one of the disks? This is a part of a bigger problem. So, I...

Homework Statement Consider a magnetron. It consists of an electron-emitting filament at the center of a cylindrical anode situated in a uniform magnetic field. Electrons of charge e and mass m are emitted with negligible velocity from the filament. What is the minimum potential...

I firstly calculated D for the r> r1 and then calculated E for r1<r< r2. Using that I calculated V taking integration of E.dl. The part I was not sure about from here was about optmiizing E but how I did it was since, we are supposed to minimize E, which is same as maximizing Capacitance for...

but the question tells me to find net force on a second dipole. so, why do i need to find the field due to the charge in this case? i am even more confused.

Homework Statement I need to find force between two dipoles. I was thinking of finding F between all the four charges separately and then using superposition principle to get the net charge. but is there an easier way. Say, if I use the formula of E (dipole) for one dipole and multiply it...

Homework Statement Assume a spherical electrode of radius r1 and a spherical metal tank of radius r2. The electrode is inside the metal tank. The electrode must operate at a voltage V with respect to a tank. The tank is grounded (V=0). Now let's focus on the electric field intensity at the...