Recent content by cloudone

  1. C

    Proving \Phi = 1 / r satisfies \nabla^2\Phi=0 in Cartesian coordinates

    Homework Statement Using Cartesian coordinates show that \Phi = 1 / r satisfies \nabla^2\Phi=0 for r not equals to 0. Homework Equations The Attempt at a Solution I tried to let r = x+y+z, then \nabla \Phi = ( \frac{1}{r^2} , \frac{1}{r^2}, \frac{1}{r^2}), but \nabla . \nabla \Phi is...
  2. C

    Partial derivatives and chain rule

    Homework Statement express (\frac{\partial u}{\partial s})_{v} in terms of partial derivatives of u(s,t) and t(s,v) Homework Equations The Attempt at a Solution I'm pretty stuck with this problem. I know that dv = (\frac{\partial v}{\partial s})_{t} ds + (\frac{\partial...
  3. C

    Use dimensional analysis to show that increase in g due to lead

    argh, thanks. I just realized that. I've been thinking dp as differential of p
  4. C

    Use dimensional analysis to show that increase in g due to lead

    Homework Statement A clock is placed on a floor covered with lead density \rho and thickness d. Use dimensional analysis to show that increase in gravitational field strength at the clock dueo to the layer of lead is proportional to Gd\rhoHomework Equations The Attempt at a Solution to show...
  5. C

    I-V graph of Diode using a C.R.O.

    Homework Statement In all physics textbooks, the V-I graph for diode appears like the followings http://211.233.39.205/phpBB2/forum_img/diode/diode-14.gif However, when I conducted the experiment with a 1N4001 diode and 12V-AC, similar graph was found, the the graph seemed to have reflected...