5.4 — Newton’s third law — action and reaction
If object A exerts a force on object B, then B exerts an equal-magnitude, opposite-direction force on A.
5.5 — Weight and mass
Mass (m): an intrinsic property of an object — amount of matter. Unit kg. Constant — independent of location.
5.6 — Friction
Friction is the force that either holds an object in place or slows it down when sliding on a surface. Opposes motion (or the tendency to move). Two kinds:
5.7 — Applications — pulleys, inclined planes, elevators
Classic systems that appear in every exam and real-world problem.
5.8 — Worked problems — Newton’s laws in action
Seven worked problems exercising all Chapter 5 tools.
5.9 — Practice problems — 20 exercises for mastery
Twenty problems in three tiers. Answers at the end.
5.10 — Q&A — Frequently asked questions for Chapter 5
1) Is the first law independent of the second?
Chapter 6 — Advanced applications of Newton’s laws
Advanced Newton’s laws: circular dynamics, non-inertial frames, drag force, terminal velocity, and the four fundamental forces of nature.
6.1 — Newton’s laws revisited for applications
Before diving into applications, a compact review of Chapter 5’s three laws:
6.2 — Dynamics of circular motion — centripetal force
From §4.4 we know that an object in uniform circular motion has centripetal acceleration ac = v^2/r toward the center. The key question now: which…
