Physics Review Unit 5 Momentum | Concordia University Wisconsin

University:
Concordia University Wisconsin
Course:
PHYS 1514 | General Physics I
Academic year:

2019
Views:

284

Pages:

4
Author:

zbrkanogiorr

Unit 5: Momentum Momentum: Momentum describes a mass in motion and measures how much force is required to stop it. Momentum is a vector quantity that all moving objects possess. An object’s momentum would change if its velocity changes (acceleration occurs). If an object undergoes an acceleration, it must be experiencing a force. A force will cause a change in momentum. Impulse: Applying an external force to an object over a time interval results in a change in momentum. The impulse experienced by the object equals the change in momentum of the object. Impulse Momentum Theorem Law of Conservation of Momentum - The total momentum of the system is equal to the total momentum of the system after the collision. P before=P after - Newton’s Third Law and Momentum - According to Newton’s 3rd law, when two objects interact, they exert equal and opposite forces on each other. The time that they are in contact are also equal. Therefore, the impulse they experience is equal. Since the impulse is equal, then the changes in momentum, must be equal. - Collisions - Occurs when objects collide and result in a change of motion as a result of internal forces between the objects. Collisions can be either elastic or inelastic. - Elastic collisions: Two objects collide with each other and then separate after impact. The final velocities of the two objects may not be equal. Both momentum and kinetic energy are conserved. - - Inelastic collisions: Two objects collide with each other, then move together after impact. The two objects become one larger object after the collision and have one velocity. Momentum is conserved and kinetic energy is not conserved.