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]
The apparatus in the y,ss2oxt.l z 4diagram consists of (rln9 .(thc::c,yodxqhigi * a solid cylinder of radius $1 \mathrm{~cm}$ attached at the center to two disks of radius $2 \mathrm{~cm}$. It is placed on a surface where it can roll, but will not slip. A thread is wound around the central cylinder. When the thread is pulled at the angle $\theta=90^{\circ}$ to the horizontal (directly up), the apparatus rolls to the right. Which below is the largest value of $\theta$ for which it will not roll to the right when pulling on the thread?
A. $\theta=15^{\circ}$
B. $\theta=30^{\circ}$
C. $\theta=45^{\circ}$
D. $\theta=60^{\circ}$
E. None, the apparatus will always roll to the right
参考答案: A
本题详细解析:
暂无
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