Credit and/or file tracking information follows to the divider line:

Credit/Permission: © William M. Connolley (AKA User:William M. Connolley), 2009 (uploaded to Wikimedia Commons by User::Justass, 2009) / Creative Commons CC BY-SA 3.0.
Image link: Wikipedia: File:Tidal-forces.svg.
Local file: local link: tidal_force.html.
Extended file: Mechanics file: tidal_force_4.html.
File: Mechanics file: tidal_force.html.