A quarterback throws a pass that is a perfect spiral. In other words, the football does not wobble, but spins smoothly about an exis passing through eaach end of the ball. Suppose the ball spins at 7.7 rev/s. In addition, the ball is thrown with a linear speed of 19 m/s at an angle of 55 deg with respect to the ground. If the ball is caught at the same height at which it left the quarterback;s hand, how many revolutions has the ball made while in the air?