During this unit, students will investigate physical science concepts related to forces and motion. They will then synthesize and apply their learning to grapple with the question of whether speed limits should be lowered to reduce traffic accidents. Through engagement in several hands-on activities, as well as the development of research-based arguments, students relate physical concepts to their everyday lives and to the functioning of society. The key science concepts in this unit are forces, friction, motion, momentum, mass, gravity, and velocity. This sample chapter also includes the Table of Contents, Introduction, and Index.