This document summarizes key concepts from several chapters in an introductory physics textbook, including circular and rotational motion, torque, universal gravity, gravitational fields, satellite motion, special relativity, vibrations, and waves. Special relativity describes how time is affected by constant velocity motion through space. Albert Einstein first understood the relationship between space and time by introducing the Special Theory of Relativity. Vibrations transfer energy through back-and-forth motion like a swinging pendulum, while waves transfer energy without transferring matter between source and receiver.