Impulse & Momentum Chapter 9

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

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

Rearrange

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

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

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

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.

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.

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?