All Physics Faculty Publications
Document Type
Article
Journal/Book Title/Conference
European Journal of Physics
Author ORCID Identifier
Boyd F. Edwards: https://orcid.org/0000-0002-2309-1350
John M. Edwards: https://orcid.org/0000-0002-0882-312X
Volume
43
Issue
1
Publisher
Institute of Physics Publishing Ltd.
Publication Date
11-9-2021
Award Number
NSF, Division of Chemistry (CHE) 1808225
Funder
NSF, Division of Chemistry (CHE)
First Page
1
Last Page
20
Abstract
We explore the forces that shape our spheroidal Earth and the forces that govern the motion of a puck that slides without friction on its surface. The Earth's stable spheroidal shape (apart from small-scale surface features) is determined by balancing the gravitational forces that hold it together against the centrifugal forces that try to tear it apart. The motion of a puck on its surface differs profoundly from motion on a sphere because the Earth's spheroidal deformations neutralize the centrifugal and gravitational forces on the puck, leaving only the Coriolis force to govern the motion. Yet the Earth's spheroidal deformations are small and difficult to see in scale drawings. To assist students in exploring the crucial role of these deformations for motion on the Earth's surface, we develop a model of uniformly rotating homogeneous earth-like planets with arbitrary eccentricities and arbitrary angular speeds of rotation, derive equations of motion for a puck sliding on the frictionless surface of such a planet, and introduce CorioVis software for visualizing this motion. By construction, this model replicates the rotational properties of the reference spheroid that is used in terrestrial cartography, geodesy, and the global positioning system.
Recommended Citation
Edwards, Boyd F. and Edwards, John M., "Geodetic Model for Teaching Motion on the Earth's Spheroidal Surface" (2021). All Physics Faculty Publications. Paper 2129.
https://digitalcommons.usu.edu/physics_facpub/2129
Comments
This is the Accepted Manuscript version of an article accepted for publication in European Journal of Physics. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at https://doi.org/10.1088/1361-6404/ac0e87.