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AP Course

AP Physics C: Mechanics

Updated for the AP Physics C: Mechanics framework effective fall 2024, with calculus-based derivations, labs, quizzes, and practice.

Build calculus-based mechanics with original derivations, experiments, quizzes, and practice sets.

Lessons
Scalars and VectorsDisplacement, Velocity, and AccelerationRepresenting MotionReference Frames and Relative MotionMotion in Two or Three DimensionsSystems and Center of MassForces and Free-Body DiagramsNewton’s Third LawNewton’s First LawNewton’s Second LawGravitational ForceKinetic and Static FrictionSpring ForcesResistive 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 OscillatorsSimple and Physical Pendulums
Quizzes
Practice Problems Formula notes, diagrams, and practice sets will be added here.

AP Physics C: Mechanics · Unit 3 · Topic 3.2

Work

Line integrals, potential functions, and power track energy transfer when forces vary with position or time.

1. Topic Lens

Work is studied through work, energy, and power. Connect the system boundary, interacting parts, and measurable evidence before applying a formula.

\[W=\int_{x_i}^{x_f}F_x(x)\,dx\]

2. Why the Formula Works

The relationship is built from definitions and conservation reasoning:

  1. Use F=ma and the chain rule a=v dv/dx.
  2. Then F dx=mv dv, so accumulated work becomes an integral over speed.
  3. Evaluating the bounds gives the change in kinetic energy.
\[W_{\text{net}}=\int mv\,dv=\frac12m(v_f^2-v_i^2)\]

3. Detailed Visual Model

Pixel diagram for WorkOriginal schematic connecting Work to Work, Energy, and Power.
Work: an original pixel-style model. Use it as a schematic, not a literal scale drawing.

4. Worked Example and Lab Link

A one-dimensional force is F(x)=2x N from x=0 to 3 m. Find its work.

Answer: W=∫₀³2x dx=[x²]₀³=9 J.

Investigation idea: Use a force sensor to obtain a nonconstant F-x curve and compare numerical area with measured ΔK.

Common trap: For a conservative force, F=-dU/dx; missing the minus sign reverses stability conclusions.

Checkpoint · Topic 3.2

Explain how work supports or limits this conclusion: W=∫₀³2x dx=[x²]₀³=9 J.

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