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Unformatted text preview: UM L =0 so Lf Li =0 so Lf = Li (note : bold means vector) Idisc = 400 kgm2, Istudent at edge of disc = 400 kgm2 Iinitial = Istudent + Idisc = 800kgm2 When student walks to center he contributes nothing to the I of the system, since r = 0 So, If = 400 kgm2 Lf = Li - Ii i = If f 800 kgm2 * I = 400 kgm2 * f So f = 2 I A disc is spinning with an angular velocity of initial when a large amount of di-ethyl goop is dropped onto it from above. If the goop is uniformly distributed on the top surface of the disc and doubles of mass of the disc, what is the new angular velocity of the disc, final . Assume the disc spins with no friction. Explain. How, qualitatively, would you change your answer if all of the goop landed near the center of the di...
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This document was uploaded on 03/13/2014 for the course PHYS 7B at UC Davis.
- Winter '10