本题目来源于试卷: Physics Unit26: Special Theory of Relativity，类别为 国际高中通用物理
[单选题]
A spear is thrown by you l nmw 19w+q u.qus x,kb907znn18djz sat a very high speed. As itjq0g j ypa+a95kwq a). passes, you measure its length at one-half its normal wayqjq.5+aak j)gp 09length. From this measurement, you conclude that the moving 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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