electrostatic problem

Electrostatics - Electrostatics is the branch of science that deals with the phenomena arising from stationary or slowly moving electric charges. Since classical antiquity it was known that some materials such as amber attract light particles after rubbing. The Greek word for amber, ήλεκτ�ον..

Electrostatics - Electrostatics is the branch of science that deals with the phenomena arising from stationary or slow-moving electric charge s. Since classical antiquity it was known that some materials such as amber attract light particles after rubbing. The Greek word for amber, ήλεκτ�ον..

  Relaxation Method for Electrostatic Problemsdemonstrations.wolfram.com The Wolfram Demonstrations Project contains thousands of free interactive visualizations, with new entries added daily. We use the relaxation method to approximate solutions of Laplace's equation. Starting with a grid of points with fixed values at the boundaries, the value of the solution at a point is the mean of its four neighbors. (This can be seen with a Taylor seri... Contributed by: Enrique Zeleny

  ElectrostaticsLesson one - the electrostatic charge

Question : A charge of +q is located at the origin, while an identical charge is located on the x axis at x = 0.45 m. A third charge of +5 q is located on the x axis at such a place that the net electrostatic force on the charge at the origin doubles, its direction remaining unchanged. Where should the third charge be located? x = ? m

Answer : Charge repulsion falls off as the square of the distance, so for a +5q charge to offer the same repulsion as a +1q charge, (thus doubling the force), it will have to located further out. 1q/0.45m = 5q/(x^2) x^2 = 5*0.45 x = sqrt( 2.25 ) = 1.5 the 5q charge will have to be located at +1.5 meters on x axis.

Question : Honeybees actively foraging in the field have been found to be electrically charged, due largely to air resistance as they fly. The charges carried by a bee, which can be as great as 89 pC, is thought to play a significant role in pollination -- the bee can detach grains of pollen from a distance, like a charged comb attracting bits of paper. Given the force required to detach pollen from an avocado stigma is 4.1 10-10 N, find the maximum distance at which the electrostatic force between a bee ..

Answer : Force = 4.1e-10 (N) charge = q = 89e-12 (C) Since the force is: q^2/(4*pi*epsilon0)/distance^2= 89^2 * e-24 * 8.988e9/distance^2 4.1e-10 = 89^2 * 8.988 * e-15 / distance^2 distance = sqrt((8.988*89^2/4.1)*e(-5)) = sqrt(0.8988*0.89^2/4.1) = 0.4167 (m) Well, that's the number - which seems unreasonably high! But remember that, in fact, there is no reason to believe that the pollen is really charged. What is more likely is that the electrical charge of the bee, when it's brought near the pollen, induces a polarization in the pollen that can be attracted by the bee's charge. But that will happen at a much closer distance than the one calculated for a real (not polarization-induced) charge.