When the ball is thrown into the channel as in the demonstration shown in Fig. 1~b!, it enters with some initial negative vertical velocity, an initial positive horizontal velocity, and an arbitrary spin. By using Eq. ~36!,
When the ball is thrown into the channel as in the demonstrationshown in Fig. 1~b!, it enters with some initial negativevertical velocity, an initial positive horizontal velocity,and an arbitrary spin. By using Eq. ~36!,