Unit 2: Force and Translational Dynamics

Unit 2 is Newton's laws. Start every problem with a free-body diagram, then write Newton's second law along each axis. Remember third-law pairs act on different objects and are always equal in magnitude. You'll handle inclines, connected systems, pulleys, static vs. kinetic friction, springs (F = kx), and center of mass. The unit closes with circular motion (net force points toward the center, F = mv²/r) and universal gravitation, where force falls off as 1/r².