Bill kicks a rock off the top of his apartment building. it strikes a window across the street 13 m away. the acceleration of gravity is 9.8 m/s 2 . if the window is 25 m below the position where bill contacted the rock, how long was it in the air? answer in units of s.

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