§161 Coulomb’ s force law for pointlike charges 5. The principle of superposition The total electrical force on given charge is the vector sum of the electrical forces caused by the other charges, calculated as if each acted alone Fw=F1+F2+… Q Q3°F3F2 816.2 The electric field of static charge and electric field lines 1. The definition of electric field of static charge F at point electric field E qt The electric field at a point in space is the force per Coulomb RE at that point(N/C), direct the direction of force exerted on a positive test charge Electric field Test charge is small enough, does not alter the distribution of the charges creating the field 66 §16.1 Coulomb’s force law for pointlike charges 5. The principle of superposition The total electrical force on given charge is the vector sum of the electrical forces caused by the other charges, calculated as if each acted alone. L r r r Ftotal = F1 + F2 + q Q1 Q3 Q2 + + + − F1 r F3 r F2 r §16.2 The electric field of static charge and electric field lines 1. The definition of electric field of static charge test q F E r r electric field = Test charge is small enough, does not alter the distribution of the charges creating the field. The electric field at a point in space is the force per Coulomb at that point(N/C), direct the direction of force exerted on a positive test charge