IInsomniaStudyroom
Focus music
Pomodoro
25:00

AP Course

AP Physics 1

Updated for the AP Physics 1 framework effective fall 2024, including mechanics, rotation, oscillations, and fluids.

Study every current unit through original concept lessons, formula derivations, experiments, quizzes, and practice sets.

Lessons
Scalars and Vectors in One DimensionDisplacement, Velocity, and AccelerationRepresenting MotionReference Frames and Relative MotionVectors and Motion in Two DimensionsSystems and Center of MassForces and Free-Body DiagramsNewton's Third LawNewton's First LawNewton's Second LawGravitational ForceKinetic and Static FrictionSpring ForcesCircular MotionTranslational Kinetic EnergyWorkPotential EnergyConservation of EnergyPowerLinear MomentumChange in Momentum and ImpulseConservation of Linear MomentumElastic and Inelastic CollisionsRotational KinematicsConnecting Linear and Rotational MotionTorqueRotational InertiaRotational Equilibrium and Newton’s First Law in Rotational FormNewton’s Second Law in Rotational FormRotational Kinetic EnergyTorque and WorkAngular Momentum and Angular ImpulseConservation of Angular MomentumRollingMotion of Orbiting SatellitesDefining Simple Harmonic Motion (SHM)Frequency and Period of SHMRepresenting and Analyzing SHMEnergy of Simple Harmonic OscillatorsInternal Structure and DensityPressureFluids and Newton’s LawsFluids and Conservation Laws
Quizzes
Practice Problems Formula notes, diagrams, and practice sets will be added here.

AP Physics 1 · Unit 4 · Topic 4.3

Conservation of Linear Momentum

Impulse changes momentum, while isolated-system momentum organizes collisions and explosions.

1. Topic Lens

Conservation of Linear Momentum is studied through linear momentum. Connect the system boundary, interacting parts, and measurable evidence before applying a formula.

\[\vec J=\Delta\vec p\]

2. Why the Formula Works

The relationship is built from definitions and conservation reasoning:

  1. Newton's second law can be written as net force equals rate of change of momentum.
  2. Integrate force over the interaction time.
  3. For constant mass, the momentum change is m(v_f-v_i).
\[\int\vec F\,dt=m\vec v_f-m\vec v_i\]

3. Detailed Visual Model

Pixel diagram for Conservation of Linear MomentumOriginal schematic connecting Conservation of Linear Momentum to Linear Momentum.
Conservation of Linear Momentum: an original pixel-style model. Use it as a schematic, not a literal scale drawing.

4. Worked Example and Lab Link

A 0.50 kg ball changes velocity from +4 m/s to -2 m/s. Find its impulse.

Answer: J=0.50(-2-4)=-3.0 N·s.

Investigation idea: Measure cart velocities before and after several collision types and test total momentum with uncertainty.

Common trap: Kinetic energy is not conserved in every collision even when momentum is approximately conserved.

Checkpoint · Topic 4.3

Explain how conservation of linear momentum supports or limits this conclusion: J=0.50(-2-4)=-3.0 N·s.

Official curriculum reference: College Board AP Physics 1 course page. The explanation and worked example are independently written for this study site.