An astronaut on the moon throws a baseball upward. The astronaut is 6​ ft, 6 in.​ tall, and the initial velocity of the ball is 40 ft per sec. The height s of the ball in feet is given by the equation s equals negative 2.7 t squared plus 40 t plus 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 16 ft above the​ moon's surface? After enter your response here seconds the ball will be 16 ft above the​ moon's surface. ​(Round to the nearest hundredth as needed. Use a comma to separate answers as​ needed.)