Momentum Flashcards
Momentum
Inertia in motion
Momentum = mass x velocity
Changing momentum
Depends on m, v, and force and time
Impulse
Impulse = quantity of force x time interval Impulse = Ft
Impulse and momentum
Impulse = change in momentum Ft = change(mv)
Change of momentum and impulse are ALWAYS linked
Decreasing momentum
It takes the same impulse to decrease momentum to zero if an object hits a wall or hay stack.
- impulse is the same, no matter how the object is stopped.
- impulse does not mean same amount of force or time, but same PRODCUT of Ft.
- less force requires more time
Bounce
When an object bounces, the impulses are greater than when the object comes to a stop
Properties of momentum
- only an impulse external to a system can change the momentum of the system
- momentum has both direction and magnitude
- if there is no net external force acting on the system, there is not net impulse on the system and no net change in momentum
Law of conservation of momentum
- in the absence of an external force, the momentum of a system remains unchanged
Collisions
- momentum is conserved in collisions
- net momentum of a system of colliding objects is unchanged before, during, and after the collision because the forces are internal forces (acting and reacting within the system itself)
Net momentum before collision = net momentum after collision
Elastic collision
Colliding objects rebound without lasting deformation or general toon of heat
Inelastic collision
When objects become entangles during the collisions, characterized by deformation, or generation of heat, or both.
Complicated collisions
The magnitude of the resulting momentum upon collision will not simply equal the sum of the two momenta before collision BUT the net momentum remains unchanged in any collision regardless of the angle between the paths of the colliding objects
Parallelogram rule
Construct a parallelogram in which the two vectors are adjacent sides—the diagonal of the parallelogram shows the resultant
