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A person stands on a platform, initially at rest, that can
Chapter 2, Problem 66P(choose chapter or problem)
(II) A person stands on a platform, initially at rest, that can rotate freely without friction. The moment of inertia of the person plus the platform is \(I_p\). The person holds a spinning bicycle wheel with its axis horizontal. The wheel has moment of inertia \(I_w\) and angular velocity \(\omega_{\mathrm{W}}\), What will be the angular velocity \(\omega_{\mathrm{p}}\) of the platform if the person moves the axis of the wheel so that it points
(a) vertically upward,
(b) at a \(60^{\circ}\) angle to the vertical,
(c) vertically downward?
(d) What will \(\omega_{\mathrm{p}}\) be if the person reaches up and stops the wheel in part (a)?
Questions & Answers
QUESTION:
(II) A person stands on a platform, initially at rest, that can rotate freely without friction. The moment of inertia of the person plus the platform is \(I_p\). The person holds a spinning bicycle wheel with its axis horizontal. The wheel has moment of inertia \(I_w\) and angular velocity \(\omega_{\mathrm{W}}\), What will be the angular velocity \(\omega_{\mathrm{p}}\) of the platform if the person moves the axis of the wheel so that it points
(a) vertically upward,
(b) at a \(60^{\circ}\) angle to the vertical,
(c) vertically downward?
(d) What will \(\omega_{\mathrm{p}}\) be if the person reaches up and stops the wheel in part (a)?
ANSWER:Step-by-step solution
Step 1 of 5
Initially, the total angular momentum about the vertical axis of rotation is zero.
As there is no torque, the total angular momentum of the platform and wheel about this vertical axis must be zero and will remain conserved.