A hot air balloon decends toward the ground with a velocity of (1.6 m/s). A champagne bottle is opened to celebrate takeoff, expelling the cork horizontally with a velocity of (4.0 m/s) relative to the balloon. When opened, the bottle is 6.2 m above the ground. (Neglect air resistance.) (a) What is the initial velocity of the cork, as seen by an observer on the ground? = ( m/s) + ( m/s) (b) What is the speed of the cork, and its initial direction of motion, as seen by the same observer? Speed m/s Direction ° below the horizontal (c) Determine the maximum height above the ground attained by the cork. m (d) How long does the cork remain in the air?