A man standing in an elevator observes a screw fall from the ceiling. The ceiling is 3 m above the floor.
(a) If the elevator is moving upward with a speed of 2.2`m//s` how long does it takes for the screw to hit the floor?
(b) How long is the screw in air if the elevator starts from rest when the screw falls and moves upwards with a constant acceleration of `a=4.0m//s^(2)`?