An object is moving initially with a velocity of 5.1 m/s. After 3.8 s the object's velocity is -2.7 m/s. What is the object's average acceleration during this time?

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