1. (17.2) The rotor of an electric motor has an angular velocity of 3600 rpm when the load and power are cut off. The 110-lb rotor, which has a centroidal radius of gyration of 9 in., then coasts to rest. Knowing that the kinetic friction of the rotor produces a couple with a magnitude of 2.5 lb-ft, determine the number of revolutions that the rotor executes before coming to rest. Notes: The work done by friction is negative. You may convert all units to SI system if you have difficulty in dealing with the English system of measurement.

1. (17.2) The rotor of an electric motor has an angular velocity of 3600 rpm when the load and power are cut off. The 110-lb rotor, which has a centroidal radius of gyration of 9 in., then coasts to rest. Knowing that the kinetic friction of the rotor produces a couple with a magnitude of 2.5 lb-ft, determine the number of revolutions that the rotor executes before coming to rest. Notes: The work done by friction is negative. You may convert all units to SI system if you have difficulty in dealing with the English system of measurement.

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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