[刀马2012]

作者: big bird

Acceleration (a) is not important here, velocity at the time of contact and the duration of the contact are! The law to use is not Newton's 2nd law of...

我的目的是说明视频中2000多磅的打击力是胡扯，期待鸟先生为我们做深入分析。本人洗耳恭听，也算重新学习一遍忘得差不多的物理知识。