Bound and unbound orbits; escape velocity. Various sources of energy, energy storage, energy conversion, and the world's energy consumption are discussed. This lecture is part of 8.01 Physics I: Classical Mechanics, as taught in Fall 1999 by Dr. Walter Lewin at MIT. This video was formerly hosted on the YouTube channel MIT OpenCourseWare. This version was downloaded from the Internet Archive, at https://archive.org/details/MIT8.01F99/. Attribution: MIT OpenCourseWare License: Creative Commons BY-NC-SA 3.0 US To view a copy of this license, visit http://creativecommons.org/licenses/b.... More information at http://ocw.mit.edu/terms/. This YouTube channel is independently operated. It is not affiliated with MIT, MIT OpenCourseWare, the Internet Archive, or Dr. Lewin, nor do they endorse any content on this channel.