本题目来源于试卷: gc physics textbook chapter 6 problems，类别为 IB物理学
[问答题]
Seasoned hikers prefer to step over a fallen ld;+el:6gjk5 :zomy3e+yoh c m og in their path ratheq vh-ac-jgux 0 ef9+q,r than stepping on top and jumping downg qcq-jfh,xe9-av0+ u on the other side. Explain.
参考答案: Stepping on the
log requires that the entire body mass be raised up the height of the log,
requiring work (that is not recoverable) proportional to the entire body
mass. Stepping over the log only
requires the raising of the legs, making for a small mass being raised and thus
less work. Also, when jumping down,
energy is expended to stop the “fall” from the log. The potential energy that you had at the top
of the log is lost when coming down from the log.
本题详细解析:
暂无
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