An object is propelled vertically upward from the ground with an initial velocity of 78.4 m/s. The signed distance s (in meters) of the object from the ground after / seconds is given by the position function s = s (() = -4.9 + 78.4. (a) What is the velocity of the object at time ? (Express numbers in exact form. Use symbolic notation and fractions where needed.) D(1) = m/s (b) When will the object reach its maximum height? (Use decimal notation. Give an exact answer.) (c) What is the maximum height? (Use decimal notation. Give an exact answer.) maximum height: m (d) What is the acceleration of the object at any time ? (Use decimal notation. Give an exact answer.) a (1) =(e) How long is the object in the air? (Use decimal notation. Give an exact answer.) time in the air: (f) What is the velocity of the object upon impact with the ground? What is its speed? (Use decimal notation. Give exact answers.) velocity: m/s speed: m/s (g) What is the total distance traveled by the object? (Use decimal notation. Give an exact answer.) total distance: m