本题目来源于试卷: Physics Unit26: Special Theory of Relativity，类别为 通用国际物理
[单选题]
A spear is thrown by you at a very hi/w5 2f d-lwtas- crd.ugh speed. As it passes, you meh4 *x +duqrt0yasure its length at one-half its normal length. From this measurement, you conclude that the movy0xt +*d4rquhing spear's mass must be
A. one-half its rest mass.
B. twice its rest mass.
C. four times its rest mass.
D. none of the given answers
参考答案: B
本题详细解析:
暂无
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