1. CP Physics
Momentum notes

2. Momentum Idea of inertia in motion
Equation: p = mv, p = momentum, kgm/s
Very massive objects moving slowly can have large momentum while very small objects moving extremely fast can have large momentums
Ex. Aircraft carrier vs. bullet (Mv = mV)
Objects at rest have no momentum

3. Impulse
Impulse = changing momentum – must either change mass or velocity
Usually object’s velocity changes
Changing velocity requires object to be accelerated – requires net force to act on object

4. Impulse, part 2 Two factors involved in changing momentum
Net force applied - more force = bigger change
Time force is applied – longer time = bigger change
Impulse = force acting over time to change the momentum of an object
Equations:
∆p = m∆v
∆p = F∆t
F∆t = m∆v

5. Changing Momentum Increasing momentum Apply greatest force possible
Extend time of contact
Largest change in momentum – apply great force over long time
Examples – golfer and baseball players following through when hitting golf ball or baseball

6. Changing Momentum Decreasing momentum – over long time
Want to lessen force experienced
Extend length of time – will decrease amount of force experienced to less
Examples – car safety devices such as airbags, bumpers, padded dashboards, safety nets

7. Changing Momentum Decreasing momentum – over short time
If momentum changes over very short time – then force experienced very large
Want very short time if need very large force exerted
Example – breaking blocks in karate