Final answer:
Top-spin on a hook ball in bowling is the result of imparting angular momentum to the ball often achieved through a wrist twist or specific finger motion by the bowler, causing the ball to curve as it travels down the lane.
Step-by-step explanation:
Top-Spin on a Hook Ball in Bowling
The phenomena of top-spin on a hook ball in bowling can be understood through the concepts of angular momentum and physical forces. When a bowler releases a ball with a twist of the wrist or a certain finger motion, angular momentum is imparted to the ball. This spin influences the trajectory of the ball after it touches the lane, causing it to curve or hook towards the pins. Similarly, this mechanism can be seen in sports such as football, where a quarterback gives the football a spin for more stable flight, or in shooting, where a rifle bullet is spun for better accuracy.
Analogous to the tennis scenario explained in Figure 10.25, where hitting the ball off the racket's center of percussion, or sweet spot, can add top-spin with reduced vibrations. This also explains why a well-thrown hook ball in bowling will not only curve but also cause the bowling pins to fly and spin, due to the transfer of both linear and angular momentum upon collision.