While lifeguarding, Jenny is twirling a whistle in uniform circular motion next to herself (the whistle is moving in a vertical plane). The radius of the circular path is 55 centimeter. The cord slips from her hands and the whistle moves off tangentially, with the initial velocity of the whistle making an angle of 30 degree with the horizontal direction. The whistle lands a horizontal distance of 15 meter away from where it slipped (suppose it returned to the similar height from which it left uniform circular motion). Find the period of whistle while in uniform circular motion?