This document defines and provides examples of momentum and impulse. It states that momentum depends on an object's mass and velocity, and can be calculated using the equation p=mv. Impulse is defined as the force applied over time, or the change in an object's momentum. The impulse-momentum theorem states that the impulse acting on an object equals its change in momentum. Examples are provided to illustrate momentum, impulse, and how applying a force over a longer period of time through an airbag can reduce the impact.

2. • “mass in motion”
• Depends on mass and
velocity of an object.
• Equation (See Ref. Tables):
p = mv
Units: kg*m/s
• Vector quantity: (same
direction as object’s velocity)

3. • Example: What is the momentum
of a 40,000 kg train going 2m/s? What is
the momentum of a 2,000 kg car going 40
m/s? How do they compare?

4. • Example: A 1000 kg car
accelerates from rest to 30
m/s. Find the following:
A. Car’s initial momentum
B. Car’s final momentum
C. Car’s change in momentum

5. •What causes a change in
velocity (acceleration)?
FORCES!!
•Definition: force times the
duration of the collision

6. •Equation (see ref. tabs)
J = Fnet t = Δp
•Units: N*s = kg*m/s
•Example: A ball is stopped by a 100 N
force over a time period of 2 s.
Determine the impulse acting on the ball.

7. •Impulse-Momentum Theorem:
The impulse acting on an object is equal to the
object’s change in momentum
Stopping an egg against a brick wall and stopping
an egg against a bed sheet (video)
Football helmets and pads decrease the force by
extending the time of the impact (video)

8. • An airbag spreads the force over a greater
time, therefore decreasing the magnitude of
the force acting on the person

9. 1.A force of 20 N acts on a 2.9 kg mass
for 10 s.
A. What is the impulse of the object?
B. What is the change in speed of the
object?

10. 2. A 2200 kg SUV traveling 26 m/s can
be stopped in 5.5 seconds in a panic
stop, or in 0.22 seconds if it hits a
concrete wall.
What is the average force that is exerted
on the SUV in each case?