Why reaction force must exist

Which graph best represents the relationship between the electric current and the rate at which a magnet is turning inside an electric generator?

What are chlorofluorocarbons and what impact do they have on the atmosphere?

Point charges q1 = 51 µc and q2 = −27 µc are placed 1.0 m apart, with q2 on the right. what is the force (in n) on a third charge q3 = 19 µc placed midway between q1 and q2? (assume the positive direction is to the right. indicate the direction with the sign of your answer.)