本题目来源于试卷: Circular Motion，类别为 美国物理杯赛(Physics Bowl)
[单选题]
07.22: A mass m is pulled outward until the string of srn+h4;t n.s2ko)ciwk/rt. qlength L to which s*mo msxf9z7q;lu2 .u,k1b juit is attached makes a 90- def1oz 2s qkuxl,*m 7mu; j9b.usgree angle with the vertical. The mass is released from rest and swings through a circular arc. What is the tension in the string when the mass swings through the bottom ofthe arc?
A. 0
B. $mg$
C. $2mg$
D. $3mg$
E. It cannot be determined.
参考答案: D
本题详细解析:
暂无
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