4. An airplane initially at rest accelerates down a runway. It reaches a velocity of 55 m/s before it lifts off the ground. It takes a time of 8 seconds to do this. a. What is the acceleration of the airplane? b. Find the distance the airplane travels before it lifts off. 5. A baseball player throws a baseball upward. The ball reaches a maximum height of 12 meters. a. What is the initial velocity of the ball? b. What is the total time the ball spends in the air