A charge of 6.4 � 10�7 c experiences an electric force of 1.8 � 10�1 n. what is the electric field strength?
a) 1.1 � 10�7 n/c
b) 3.6 � 10�6 n/c
c) 8.2 � 100 n/c
d) 2.8 � 105 n/c