An object while in flight has an acceleration of at 0032 The

An object while in flight has an acceleration of a(t)= (0,0,-32). The initial velocity of the object is v(0)=(8,4,16) and initial position r(0)=(1,2,0). At what time t does not equal 0 and what position does the object cross the xy plane (this would represent where the object would hit the ground). How far did the object travel during the flight?