2_11 - PHY 5346 HW Set 4 Solutions Kimel 4 2.11 The system...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: PHY 5346 HW Set 4 Solutions Kimel 4. 2.11 The system is pictured in the following figure: a) The potential for a line charge is (see problem 2.3) ln rr r 2 0 Thus for this system r 2 ln 0 r R r 2 ln 0 r R r To determine and R , we need two conditions: I) As r , we want b r 0, so . or ln b R R b or b R R b This is an equation for R with the solution bR bR ln b R bR II) b r 2 R b R The same condition we found for a sphere. b) r 4 as r r Using 4 ln 0 ln 0 r2 b4 R2 2r b cos R 2rR cos 2 b2 rR 2 r2 R2 4 1 2b 2 cos /rR 1 2R cos /r ln 1 x x r 2 4 2b 0 ln 1 0 R 2 cos 1 x2 1 x3 O x4 3 2 1 b 2 R 2 cos rR r2 b4 R2 c) 0 r |rb r ln 2r b cos R 2rR cos rb 2 r2 R2 2 1 y y 1 2y cos 2 where y R/b. Plotting / 2b 1 y2 y 2 1 2y cos , for y 2, 4, gives gy g 2 ,g 4 3 5 4 cos 1 y2 y 2 1 2y cos , 15 17 8 cos 0.5 0 -0.5 -1 -1.5 -2 -2.5 -3 1 1.5 2 2.5 3 d) If the line charges are a distance d apart, then the electric field at from is, using Gauss's law E 2 0 d The force on is LE, ie, 2 L , and the force is attractive. F L 2 0 d 2 0 d ...
View Full Document

This note was uploaded on 01/10/2012 for the course PHYSIS 506 taught by Professor Smith during the Spring '08 term at University of Arkansas Community College at Morrilton.

Ask a homework question - tutors are online