Momentum Overview — AP Physics 1
1. Unit at a Glance
This unit builds from core definitions up to a powerful problem-solving framework that simplifies analysis of interactions between objects. Momentum conservation is one of three fundamental conservation laws you will use across all of AP Physics 1, and it applies to any system with no net external force.
We progress from foundational concepts to increasingly complex applications: starting with core definitions, the impulse-momentum theorem, and momentum conservation, before moving to one-dimensional and finally two-dimensional collision problems.
Common Pitfalls
Why: Momentum is only conserved for isolated systems with no net external force acting on the system.
Why: Only elastic collisions conserve kinetic energy; all isolated collisions conserve momentum.
Why: Ignoring direction leads to incorrect cancellation or addition of momentum components.