a person with mass m stands at the outer edge of a round platform whose radius is r and whose mass is m2. the platform is rotating at a speed of ...rad/s. Assuming the platform to be a free rotating disk, what would be its angular speed if the person walked to its center?(adsbygoogle = window.adsbygoogle || []).push({});

Then the answer book says....

L(i) = L(f) because sum(torque) = 0...

How would I know the sum of the torques is zero...? Is the paragraph said.. " Assuming the platform to be a free rotating disk..." ?

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# Homework Help: General question about ang momentum throug word problem

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