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Momentum. Conceptual Physics Chapter 7. Momentum. Inertia in motion Momentum = mass x velocity(or speed) Large momentum can occur when you have a large mass or high speed or both. Impulse changes momentum. When momentum changes then mass, velocity or both change
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Momentum Conceptual Physics Chapter 7
Momentum • Inertia in motion • Momentum = mass x velocity(or speed) • Large momentum can occur when you have a large mass or high speed or both
Impulse changes momentum • When momentum changes then mass, velocity or both change Impulse is a product of force and time during which the force acts. • Force x time interval = impulse • Greater the impulse the greater the momentum change
Increasing momentum • Apply the greatest force possible for as long as possible • Golf swing, baseball swing • Impact= force • Impulse = impact force x time
Decreasing momentum • Longer impact time reduces the force of the impact and decreasing the resulting deceleration • Extend the time of impact and you reduce the force of impact • Car hitting a wall or a haystack
Bouncing • Impulses are greater when objects are bounced • Impulse to bring an object to a stop and then “throw” it again is greater than to merely stop
Conservation of Momentum • Momentum is a vector quantity • If no net force or net impulse acts on a system, the momentum of the system cannot change • Conserved means when a quantity does not change • Law of conservation of momentum-In the absence of an external force, the momentum of a system remains unchanged
Collisions • Momentum will stay the same in the system before the collision and after the collision • Elastic collisions- objects collide without being permanently deformed or generating heat • Inelastic collisions- when colliding objects become distorted or tangled
Momentum Vectors • Momentum is conserved even when the objects don’t move along a straight line • Can be calculated like other vector quantities • Example --Playing Pool. Hitting one ball transfers momentum to multiple balls moving in various directions
TPS • Spend 60 seconds thinking about what was most important in this presentation • Brainstorm with your table mate and write the two most important things you could think of • Share with the class when your teacher calls on your pair.