This text highlights key terms important for the study of development of force concept; Newton's first law of motion: inertia; Newton's second law of motion: concept of a system; Newton's third law of motion: symmetry in forces; normal, tension, & other examples of force; problem-solving strategies; further applications of Newton's laws of motion; and extended topic: the four basic forces—an introduction. Advanced Placement® and AP® are trademarks registered and/or owned by the College Board, which is not affiliated with, and does not endorse, this textbook.