Solve the all parts of given question:
Question: A parachutist bails out and freely falls 63 m. Then the parachute opens, and thereafter she decelerates at 1.6 m/s2. She reaches the ground with a speed of 2.7 m/s.
Part A: How long is the parachutist in the air?
Part B: At what height does the fall begin?
I need help to determine how long the parachutist in the air.