#### Impulse & Momentum

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Transcript Impulse & Momentum

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
v
F m a m
t
Rearrange
Ft mv
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
Ft p f pi
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 ImpulseMomentum 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?