A disk of mass 1.5 kg and radius 55 cm with a small mass of 0.09...

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A disk of mass 1.5 kg and radius 55 cm with a small mass of 0.09 kg attached at the edge is rotating at 2.5 rev/s. The small

Answer 1

Answer #1

By conservation of angular momentum,

i1 w1 = i2 w2 where i1,i2 are moment of inertia and w1,w2 are respective angular speeds

[0.5*m1r^2 + m2 r^2]*w1 = [0.5*m1r^2 ]*w2

[0.5*1.5*0.55^2+0.09*0.55^2]*2.5 = [0.5*1.5*0.55^2]*w2

w2 = [0.5*1.5*0.55^2+0.09*0.55^2]*2.5/[0.5*1.5*0.55^2]

= 2.8 rev/s answer

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Answer 2

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