Module 1
1. Module 1
1.10. Page 5
Module 1—Momentum and Impulse
Impulse Can Improve Sports Performance

© Michael Krinke/iStockphoto
This tennis player uses her racquet to change the momentum of the tennis  ball. When she took her first tennis lessons, her coach explained that when  hitting the ball with the racquet, it was important to continue to swing the  racquet after contacting the ball. This technique is often referred to as using  proper “follow through.” It is thought to be more effective than a shorter  swing at giving the ball a high velocity.
 Read
 Read
  You can find out more about the role of impulse in improving sports  performance by reading page 466 of your textbook.
   Self-Check
 Self-Check
  SC  8. Concisely explain why proper follow through increases the change in  momentum of a tennis ball being struck by a tennis racquet.
 Self-Check  Answer
 Self-Check  Answer
    
SC 8. To change the momentum of an object like a tennis ball, an athlete must supply an impulse to the ball. Since impulse is the product of the net force applied to the ball and the time interval during the interaction, the athlete attempts to maximize both the net force and the interaction time. The time interval is maximized by ensuring that the ball and the racquet are in contact for as long a time interval as possible. This is what the idea of proper follow through is all about.