1. Momentum and Collisions
Momentum and Impulse

2. Linear Momentum
Momentum – a vector quantity defined as the product of an object’s mass and velocity
Momentum = mass * velocity
p=mv
Measured in kilogram-meters per second (kgm/s)

3. Linear Momentum
You can think of momentum as a measurement of how difficult it is for an object to stop its motion
Large objects have more momentum than small ones
Fast objects have more momentum than slow ones

4. Impulse-Momentum Theorem
Changes in momentum take force and time
For situations involving constant force, we can use the Impulse-Momentum Theorem
Force * time interval = change in momentum
FΔt=Δp or FΔt=Δp=mvf-mvi

5. Impulse-Momentum Theorem
Impulse – for a constant external force, the product of the force and the time over which it acts on an object
Represented by Force * time interval
FΔt or J
Unit is kg*m/s
Used to explain the importance of follow-through in such as pool or baseball
By keeping the bat in contact with the ball longer, more force is applied to the baseball

6. Impulse-Momentum Theorem
Use the impulse-momentum theorem to determine stopping time and therefore stopping distance with the following equation:
Distance = average velocity * time interval
Δx=½(vi+vf) Δt
Objects with more mass require greater stopping times and distances than objects with less mass

7. Impulse-Momentum Theorem

8. Impulse-Momentum Theorem
Changes in momentum over longer time periods require less force
Use of safety nets and giant air mattresses by firefighters or trampolines

9. Impulse-Momentum Theorem