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4.3 Conservation of Momentum

Part of Linear Momentum in AP® Physics 1: Algebra-Based. Read the opening section, then create a free account for the full interactive lesson, practice, and progress tracking.

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Center of Mass

Before Unit 4: Linear Momentum, we have dealt with the center of mass of a system as a stationary thing which does not change if there is no external force in the system. However, the center of mass in a system can have a velocity, known as the velocity of the center of mass. This value also stays constant in a system unless there is a non-zero net external force.

vcm=∑ipimtotv_{cm}= \frac{\sum\limits_{i} p_i}{m_{tot}}
  • vcm{v_{cm}} represents the velocity of the center of mass in a system
  • pi{p_i} is the momentum of each individual object in the system
  • mtot{m_{tot}} is the total mass of the system

In this unit

4 lessons

  1. 4.1Linear MomentumPreview lesson
  2. 4.2Change in Momentum and ImpulsePreview lesson
  3. 4.3Conservation of MomentumThis lesson
  4. 4.4Elastic and Inelastic CollisionsOpen lesson

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