Work and Inertial Frames
Autor: | Richard Kaufman |
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Rok vydání: | 2017 |
Předmět: |
Physics
Inertial frame of reference Internal energy 05 social sciences Perspective (graphical) Work (physics) 050301 education General Physics and Astronomy Mechanics Kinetic energy 01 natural sciences Center of mass (relativistic) Education 0103 physical sciences 010306 general physics 0503 education Energy (signal processing) Reference frame |
Zdroj: | The Physics Teacher. 55:561-564 |
ISSN: | 0031-921X |
DOI: | 10.1119/1.5011835 |
Popis: | A fairly recent paper resolves a large discrepancy in the internal energy utilized to fire a cannon as calculated by two inertial observers. Earth and its small reaction velocity must be considered in the system so that the change in kinetic energy is calculated correctly. This paper uses a car in a similar scenario, but considers the work done by forces acting over distances. An analysis of the system must include all energy interactions, including the work done on the car and especially the (negative) work done on Earth in a moving reference frame. This shows the importance of considering the force on Earth and the distance Earth travels. For calculation of work in inertial reference frames, the center of mass perspective is shown to be useful. We also consider the energy requirements to efficiently accelerate a mass among interacting masses. |
Databáze: | OpenAIRE |
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