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Impulse and Momentum. Physics. Quick Review of Newton’s Second Law. What is Momentum?. 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). Which has More Momentum?.
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Impulse and Momentum Physics
Quick Review of Newton’s Second Law Cartoons from The Cartoon Guide to Physics by Gonick & Huffman
What is Momentum? • Mass in Motion!!! Or Inertia in Motion!!! • Vector Quantity (has direction) • Momentum = mass x velocity • p = momentum (kgm/s) • m = mass (kg) • v = velocity (m/s)
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???
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
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 = Ft
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.
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
Videos on Momentum & Impulse • Impulse • Hewitt Momentum Video • Bill Nye Momentum Video • Mythbuster Cancel Momentum Experiment