题目

一根轻质细绳能承受的最大拉力是G,现把一重为G的物体系在绳的中点,两手先并拢分别握住绳的两端,然后缓慢地左右对称分开,若想绳不断,两绳间的夹角不能超过(                                  )             A.45°   B.60°     C.120°     D. 135°                                                                                                                               答案:C
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