Recent content by confuted

  1. C

    Cannot Lift Piano: Force or Work Not Enough

    Ah, but the amount of work done is the same no matter how you lift it -- that was my point.
  2. C

    Cannot Lift Piano: Force or Work Not Enough

    You could perform enough work to lift the piano. Imagine connecting it to an intricate system of pulleys such that you could pull lightly on the rope for a very long distance of rope and lift the piano. It'd be the same amount of work (W=F*d). Think you could do it?
  3. C

    Partially Emptying a Tank Containing an Ideal Gas

    I'll give you a small hint: the phrase "the gas quickly escapes" implies that the process is adiabatic - that is, no heat is exchanged between the system and the environment. What have you done on the problem so far?
  4. C

    Radiation from an ideal LC tank circuit

    Sorry to bump my thread, but I feel like it didn't get much attention because of LaTeX being down after the move. Does anybody have some insight here?
  5. C

    Examining EM Radiation and Charge: The Truth About Emission and Movement

    As I stated, that site should have been nothing but a starting point. You want peer reviewed papers? You've got 'em. Annals of Physics, 124, 169-188 (1980) http://www.hep.princeton.edu/~mcdonald/examples/EM/boulware_ap_124_169_80.pdf http://www.springerlink.com/content/v42441306604p571/...
  6. C

    Difference between an electric dipole and a capacitor?

    A dipole is just two charges separated by some distance; consider perhaps an electron and a proton at some small distance apart. A capacitor is a much larger, tangible thing, with two conducting plates separated by a dielectric. Each plate holds some charge (lots of charges), and an electric...
  7. C

    Back Online - All Mission Critical Components Working

    Unless I'm doing something wrong, LaTeX doesn't appear to be working in new posts: x^2 https://www.physicsforums.com/showthread.php?t=265429
  8. C

    Radiation from an ideal LC tank circuit

    Consider an ideal LC tank circuit with some initial conditions such that oscillations take place. I am trying to find the amount of power radiated per cycle due to the accelerating charges (I realize that this should come out to be a very small value). Setup and solve the relevant differential...
  9. C

    Examining EM Radiation and Charge: The Truth About Emission and Movement

    There is considerable debate over whether a uniformly accelerating charge does, in fact, radiate. http://www.mathpages.com/home/kmath528/kmath528.htm" .
  10. C

    [PhD Qualifier] Liquid in a rotating arm

    Homework Statement An open glass tube of uniform bore (uniform inner diameter) is bent into the shape of an "L". One arm is immersed into a liquid of density \rho and the other arm of length l remains in the air in a horizontal orientation. The tube is rotated with constant angular speed...
  11. C

    [PhD Qualifier] Commutation relation

    I suppose I can answer (b) using my observation from (d). Let A=\frac{X}{\hbar}, B=P. Heisenberg's relation is \Delta x\Delta p \ge \frac{\hbar}{2}, so \Delta a\Delta b\ge\frac{1}{2}. Square it to get "true". Can someone verify these answers for me?
  12. C

    What Are the Probabilities of Measuring Spin Components in a Spin Singlet State?

    Homework Statement Consider a system made up of two spin 1/2 particles. Initially the system is prepared in a spin singlet state with total spin S_{total}=0. We'll define the spin components of one particle as (s_{1x},s_{1y},s_{1z}) and of the other as (s_{2x},s_{2y},s_{2z}) a. If no...
  13. C

    [PhD Qualifier] Commutation relation

    Homework Statement Two quantum mechanical operators obey the following commutation relation. [\hat{A},\hat{B}]=i Given this commutation relation which of the following are true or false? Justify your answers. a) The two observables are simultaneously diagonalizable. b) The two satisfy a...
  14. C

    Detecting Single Photon Energy

    They won't tell you the energy of the incident photon, but avalanche photodiodes (APDs) are capable of detecting single photons with fairly high probability. Cooling an APD to cryogenic temperatures will lower the dark count rate.
  15. C

    Is Charge Conserved in Proton-Helium Collision Reactions?

    Yeah, the energy for particle-antiparticle production is always 2mc^2, where m is the mass of one of the particles.
Back
Top