(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A 45 kg figure skater is spinning on the toes of her skates at 1.0 rev/s. Her arms are outstretched as far as they will go. In this orientation, the skater can be modeled as a cylindrical torso (40 kg, 20 cm average diameter, 160 cm tall) plus two rod-like arms (2.5 kg each, 66 cm long) attached to the outside of the torso. The skater then raises her arms straight above her head, where she appears to be a 45 kg, 20 cm diameter, 200 cm-tall cylinder.

2. Relevant equations

Conservation of angular momentum

Moment of Inertia

3. The attempt at a solution

L_{i}= (I_{b}+ 2(I_{a}))w_{i}

w_{i}= 6.2831 rad/s

I_{b}= (1/2)(40)(.1)(.1)

I_{a}= (1/3)(2.5)(.66)^{2}

L_{f}= (I_{f})(w_{f})

I_{f}= (1/2)(45)(.1)^{2}

L_{i}= L_{f}

Solve for w_{f}

w_{f }= (.926)(6.2831)/(.225)

Any ideas where I went wrong?

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# Homework Help: Spinning ice skater (angular momentum)

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