4. An airplane initially at rest accelerates down a runway. It reaches a velocity of 45 m/s and travels a distance of 450 meters before it lifts off the ground. a. What is the acceleration of the airplane? b. Find the amount of time it takes for the airplane to lift off. 5. A baseball player throws a baseball upward. The ball reaches a maximum height of 18 meters. a. What is the initial velocity of the ball? b. What is the total time the ball spends in the air? 6. A stone is thrown with a velocity of 20 m/s and an angle of 40. a. What maximum height does it reach? b. What is the total time the stone spends in the air? c. How far does the stone travel horizontally?