Object Height. Suppose an object is thrown straight up from the ground. The height after t seconds is given by the formuia hm = 3t3 + mt2 + 173 (a) The time in seconds, rounded to 4 decimal places, when the object reached the highest point was 0 None of the other answers 0 15.5556 5 O 0 s 0 11.6567 5 O 173 5 O 35 s (b) The height is maximized at the critical pointX : 3 because the second derivative test found 0 f'Ea) = o O f'Ea] was positive to the left ofx = a and negative to the right 0 f"(a) 2 o O f"{a)