what is the gravitational force between two students who weight 50kg and are separated by 2.0m? 1.7 x 10^ -9 N 4.2 x 10 ^ -8 N 8.3 x 10 ^ -8 N. 1.7 x 10 ^ -7 N

Which statement best describes the superposition principle? a.) if two in-phase waves arrive simultaneously at a point, their amplitudes add up b.) if two out-of-phase waves arrive simultaneously at a point, their amplitudes add up c.) if two in-phase waves arrive at a point one after another, their amplitudes add up d.) if two out-of-phase waves arrive at a point one after another, their amplitudes adds up