A student throws a long stick of length 0.11m and mass 0.5 kg into the air in such a way that the center of mass rises vertically. At the moment it leaves his hand, the stick is horizontal and the speed of the end of the stick nearest to him is zero. When the center of mass of the stick reaches its highest point, the stick is horizontal, and it has made 15 complete revolutions. How long did it take for the center of mass to reach its highest point? Assume the stick's cross sectional area and mass is uniform. The acceleration of gravity is 9.8 m/s^2. Answer in units of s.