7. Two discs are initially spinning in opposite directions. The upperdisc has rotational inertia of 10kgm² and a rotation rate of 12rad/s.The lower disc has rotational inertia of 25kgm? and a rotation rate of8rad/s. The upper disc is dropped onto the lower disc and they sticktogether. What is the rotation rate AND direction of the two discsystem?Disk 2Disk 1(a)(b)

Write the given values. Consider the counter-clockwise rotation rate of the disc as positive and the clockwise rotation rate of the disc as negative. I1=25 kg·m2ω1=8 rad/sI2=10 kg·m2ω2=-12 rad/sApply the conservation of the angular momentum, and determine the rotation rate of the two-disc system after the upper disk is dropped on the lower disk as follows. Li=LfI1ω1+I2ω2=I1+I2ωω=I1ω1+I2ω2I1+I2=25 kg·m28 rad/s+10 kg·m2-12 rad/s25 kg·m2+10 kg·m2=2.2857 rad/s≈2.3 rad/s As the counter-clockwise rotation of the disc is considered positive, the final rotation of the two-disc system will be counter-clockwise.

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7. Two discs are initially spinning in opposite directions. The upper disc has rotational inertia of 10kgm? and a rotation rate of 12rad/s. The lower disc has rotational inertia of 25kgm² and a rotation rate of 8rad/s. The upper disc is dropped onto the lower disc and they stick together. What is the rotation rate AND direction of the two disc system?

7. Two discs are initially spinning in opposite directions. The upper disc has rotational inertia of 10kgm? and a rotation rate of 12rad/s. The lower disc has rotational inertia of 25kgm² and a rotation rate of 8rad/s. The upper disc is dropped onto the lower disc and they stick together. What is the rotation rate AND direction of the two disc system?

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter1: Units, Trigonometry. And Vectors

Section: Chapter Questions

Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...

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