1. Impulse & Momentum
Chapter 9

2. Playing Baseball
Explain what happens to the baseball when the batter hits the ball
What happens to the bat?
Explain what happens when the outfielder catches the ball

3. Impulse & Momentum
Graph on page 230 shows how the force changes with time as the bat and ball are in contact.
Check out the time. 3 ms
Newton’s 2nd law states that a net force causes an acceleration

4. Rearrange

5. Impulse
The product of the average force on the object and the time interval over which the force acts
Impulse=FΔt

6. Momentum The product of mass and velocity r=mv
r is a Greek letter representing momentum
Units kilogram.meter/second

7. Impulse-Momentum Theorem
The impulse on an object equals the change in momentum of the object

8. Using the Impulse-Momentum Theorem
Remember that velocity is a vector quantity so that make momentum a vector quantity.
A baseball comes into the bat with a positive velocity and leaves with a negative velocity.

9. Using the Impulse-Momentum Theorem to Save Lives
How do you reduce the sting in catching a ball?
How can you catch an egg in a sheet without the egg breaking?
Explain with the Impulse-Momentum Theorem why air bags save lives.

10. How do you reduce the sting in catching a ball?
How can you catch an egg in a sheet without the egg breaking?
How could the force of air bags be reduced?