A focused notebook on central-force motion: reduced mass, effective potential, orbit equation, Kepler problem, and small perturbations of orbits.

For undergrad mechanics and GRE/JAM orbital questions.

• Two-body reduction and conserved quantities
• Effective potential and bounded motion
• Inverse-square force and conic sections
• Runge-Lenz vector
• Worked orbit-precession and scattering problems