E&M review
Physics C Electricity& Magnetism Review Charge Net ? charge: excess electrons Net + charge: excess ?holes? SI unit: coulomb (C) Quantum of charge: the proton charge (e) the electron charge (-e) e = 6.02 ? 10-19Coulombs Conservation of Charge The net charge in any process or reaction remains unchanged. Coulomb?s Law Calculates magnitude of force between charges Force is repulsive if charges have the same sign. Force is attractive if charges have opposite signs. F = kq1q2/r2 F: force (N) k: constant 9.0 ? 109 N m2/C2 q1, q2: charges (C) r: distance between charge centers (m) NOTE: k = 1/(4??o) where ?o = 8.85? 10-12 C2/ N m2 Multiple Forces on a Charges Ftot = ? Fi