(adsbygoogle = window.adsbygoogle || []).push({}); In 1993, a giant yo-yo of mass 480 kg and measuring about 1.9 m in radius was dropped from a crane 57 m high. Assuming that the axle of the yo-yo had a radius of r=0.1 m, find the velocity of the descent v at the end of the fall.

I know that .5mv^{2}+.5Iw^{2}=mgh, but I don't have a clue how to find w (the angular velocity).

I really don't even know where to start. The only thing I can think of is the force due to gravity creating a torque, which would allow me to solve for the angular acceleration, but even then I would need the amount of time it takes to travel 57m in order to get the angular velocity.

If someone could point me in the right direction I would appreciate it.

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# Homework Help: Torque and energy conservation of a yoyo

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