Answer:
A) The airplane slowed down. It states that the plane lands and come to a complete stop over a 53 second period.
B) It decelerates. The speed doesn't increase. It slows down.
C) The answer should be positive. Although the deceleration is slowing down the plane, it's not going at a negative speed.
D) The answer is 11.5m/s. I divided the velocity by the amount of seconds it takes to make a complete stop.
Explanation: Just cuz