Question

一根轻质细绳能承受的最大拉力为G,现将一重量为G的物体系在绳的中点,两手先并拢分别握住绳的两端,然后缓缓地左右对称分开.若想绳不断,两绳间的夹角不能超过

A.45°                                                            B.60°

C.120°                                                          D.135°

Answer 1

解析:合力一定时,两分力间夹角越大,分力越大.若想绳不断,绳子的拉力(分力)不能超过G,可由拉力等于G时求出两绳间的夹角为120°.

答案:C