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Flashcards in Chapter 6 Deck (10)
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1

Momentum

-Mass in motion
-Linear Momentum: The product of mass and velocity (p=mv)
-Vector: Magnitude and direction
-SI: kg * m/s
-Change in momentum requires a net force (F=ma)

2

Impulse

-The product of the force and time over which the force acts on an object
-SI: N*s or kg*m/s
-Equal to the change of momentum (P=mv-mv0)
-To have same change:
-Small force over long period of time
-Large force over short time

3

Collision

-Any interaction between objects in which there is an exchange of momentum and/or energy

4

Impulse Momentum Theory

-Stopping times and distances depend on this
-More mass:
-More time and/or force to stop
-Greater change of momentum must occur for mass to stop
-If the same force is applied, more massive object will travel more distance to come to stop

5

Relationship between force and time

-Inversely proportional
-If one is multiplied by 1/2, other is multiplied by 2
-Ex:
-Airbags: extends time required to stop drivers momentum, large force over short time to hit windshield (time increase--> force decrease)

6

Law of Conservation of Momentum

-The moment of all objects interacting with one another remains constant regardless of the nature of the forces between the objects
-If there is no net force, total momentum cannot change
-If internal forces= individual parts of system change, momentum= same
-Momentum= conserved

7

Inelastic Collision

-Where there is a collision between two or more objects and the final kinetic energy is different from the initial kinetic energy
-KE is lost in heat or sound (Not conserved)
-Momentum is conserved

8

Perfectly Inelastic Collision

-Two objects stick together after collision
-Max KE has been lost during collision
-Extreme case of Inelastic collision
-Momentum= conserved

9

Elastic Collision

-Total KE and momentum= conserved
-Objects collide and return to original shape
-Move separately
-Ex: Football player kicks football

10

Center of Mass

-The point at which all of the mass of an object or system may be considered to be concentrated, for the purposes of describing its linear or translational motion only