电荷,电场,电场力,大学物理课件英文版.pdf

§16.1 Coulomb’s force law for pointlike charges 1. The discovery of electrification 1The phenomenon of electrification Glass rod is rubbed with silk—positive Amber rod is rubbed with fur--negative 2electric charge is an intrinsic characteristic of the fundamental particles making up matters. 1 §16.1 Coulomb’s force law for pointlike charges 3like charges(charges with the same sign) repel each other, and unlike charges(charges with opposite electrical signs) attract each other. §16.1 Coulomb’s force law for pointlike charges 2. The properties of electric charge 1the charges are scalar; 2charges are quantization; e=1.602177*10-19C q=ne up quarks: 2e/3, down quarks: -e/3 3the total amount of electric charges is conserved in any process involving an isolated system. 3. The polarization and induction Why can comb rubbed with fur attract small pieces of paper? 2 §16.1 Coulomb’s force law for pointlike charges §16.1 Coulomb’s force law for pointlike charges insulator Electric dipole − + + + + + + + − + − + − + electrical − + − + polarization − + conductor − − + − + + induction + + + + + + − − + + + − − + − − − − − − +