本题目来源于试卷: 2011 美国F=ma物理竞赛 F=ma physics competition，类别为 美国物理杯赛(Physics Bowl)
[单选题]
An ice skater can rotate about;h-*kj ax.pm7i)es e q am3 od,(3jfxz-mr (rlh14wv qy vertical axis with an angular velocity $\omega_{0}$ by holding her arms straight out. She can then pull in her arms close to her body so that her angular velocity changes to $2 \omega_{0}$, without the application of any external torque. What is the ratio of her final rotational kinetic energy to her initial rotational kinetic energy?
A. $\sqrt{2}$
B. 2
C. $2 \sqrt{2}$
D. 4
E. 8
参考答案: A
本题详细解析:
暂无
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