1. Impulse and Momentum
Physics

2. Quick Review of Newton’s Second Law
Cartoons from The Cartoon Guide to Physics by Gonick & Huffman

3. What is Momentum? p = momentum (kgm/s) m = mass (kg)
Mass in Motion!!! Or Inertia in Motion!!!
Vector Quantity (has direction)
Momentum = mass x velocity
p = momentum (kgm/s)
m = mass (kg)
v = velocity (m/s)

5. Which has More Momentum?
Rolling Bowling ball or Basketball?
The bowling ball
Large truck traveling at 50 mph or a train at rest unloading its passengers?
The truck
WHY???

6. Fnett = (mv) How to Change Momentum? Exert an Impulse
Caused by a Outside Net Force exerted on the object over a period of time
Impulse = Fnett
Unit: 1 Ns (Newton-second)
Equal to a change in momentum
Fnett = (mv)
If NO net force or net impulse on an object, then Momentum remains constant

8. mv = F t What is Impact Force?
Net force experienced by the object when it collides or encounters another object.
Change in Momentum or Impulse will not change during impact, BUT
If you want a small Impact Force then you have to extend the time of impact.
Ex. Air bags, safety net, moving away from a punch, crumple zones in cars, baseball glove, etc.
mv = F t

10. How Impulse, Force, and Momentum are Related

11. Spreading impulse out over a longer time means that the force will be less; either way, the change in momentum of the boxing glove, fist, and arm will be the same.

12. Impulse and Bouncing Relationship
Impulse is greatest when an object bounces
Impact force will increase because there are 2 impulses acting on the object
Impulse for the hit
Impulse to bounce off
Example
Breaking boards or blocks with Karate
Hail hitting your car leaves a dent

13. Videos on Momentum & Impulse
Hewitt Momentum Video
Bill Nye Momentum Video
Mythbuster Cancel Momentum Experiment