A physics student is standing on an initially motionless, frictionless turntable with rotational inertia 0.31 kg · m2. She’s holding a wheel with rotational inertia 0.22 kg · m2 spinning at 130 rpm about a vertical axis, as in Fig. 11.8. When she turns the wheel upside down, student and turntable begin rotating at 70 rpm. (a) Find the student’s mass, considering her to be a 30-cm-diameter cylinder. (b) Neglecting the distance between the axes of the turntable and wheel, determine the work she did in turning the wheel upside down.
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