Xavier throws a tennis ball to his friend Olaf at a 20° angle relative to the ground with an initial velocity of 18 m/s. The tennis ball travels 30 m until Olaf catches it. The time the tennis ball was in the air, rounded to the nearest hundredth, is
s.

How many neutrons does element x if it’s atomic number is 28 and its mass number is 87

In which type of system is power held solely by the central government and not shared with regional governments? group of answer choices federal unitary confederate oligarchic

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