Summary Note
Key concept recap
Introduction
The chapter begins by asking what governs the motion of bodies. From common experience, we observe that an external agency is needed to start, stop, or change the motion of a body. Forces like gravity and magnetism can act even at a distance without physical contact. This chapter lays the foundation for understanding how forces relate to motion.
A key question is posed: does a body in uniform motion require a continuous external force to maintain that motion? The answer, as Galileo and Newton established, overturns the intuitive Aristotelian view and forms the bedrock of classical mechanics.