initially, there is a cylinder with a moment of inertia [tex]I_1[/tex] and angular velocity [tex]\omega_i[/tex] A second cylinder that has a moment of inertia of [tex]I_2[/tex] and is not rotatiing drops onto the first cylinder show http://home.earthlink.net/~urban-xrisis/clip_image001.jpg [Broken]. There is friction between the surfaces and the two objects reach the same angular speed of [tex]\omega_f[/tex](adsbygoogle = window.adsbygoogle || []).push({});

I need to show that the kinetic energy decreases in this interaction and also calcualte the ratio of the final rotational energy to the initial rotational energy.

[tex].5I_i \omega _i^2 = .5I_f \omega _f^2[/tex]

[tex]I_1 \omega _i^2 = (I_1+I_2) \omega _f^2[/tex]

ratio of initial to final:

[tex]\frac{\omega _i^2}{\omega _f^2} = \frac{I_1+I_2}{I_1}[/tex]

how do I show the decrease in rotational energy?

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# Homework Help: Rotational energy

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