Description

This simulation illustrates the fall of an object on a rotating Earth. The object is assumed to be on the Earth's equator, so all motion is in the equatorial plane and the simulation can be 2D. Two views are shown. The view on the left shows a frame that is co-rotating with the Earth (so the Earth itself appears to stay still). The view on the right shows an inertial frame in which the Earth is seen to rotate counterclockwise. The object (red) is released directly above the release point (yellow) with a yellow plumb line running from the object's initial location to the Eart's center. The user can adjust the simulation speed, the height from which the object is dropped, and the rotation rate of Earth.

The user can select whether or not the object should be allowed to pass through the Earth's interior (if not then the simulation pauses when the object hits Earth's surface). In addition, the user can select from various models for the gravitational force in the interior: treating the Earth as a uniform density sphere, treating the Earth as a point mass using a central force whose magnitude is always equal to the object's weight at Earth's surface, or using an inverse square central force. Finally, the user can choose whether or not to include resistive forces in the Earth's interior, with options for linear or quadratic resistance (with adjustable resistance coefficient).