An astronaut on the moon throws a baseball upward. The astronaut is 6 ft, 6 in. tall, and the initial velocity of the ball -2.71 is 40 ft per sec. The heights of the ball in feet is given by the equation s = = 2.7 +40t+6.5, where t is the number of seconds after the ball was thrown. Complete parts a and b. a. After how many seconds is the ball 20 ft above the moon's surface? After seconds the ball will be 20 ft above the moon's surface. (Round to the nearest hundredth as needed. Use a comma to separate answers as needed.)