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 pu-u :/,er yd sq(bmb( kf *xfwbbe51;mud0t0mggi r7n,zn 16dklled outward until the string of length L to which it is attached makes a 90mn r6tdn1g0g7 ,zikd0- degree 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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