问题描述：
英语翻译
the total momentum of a system of interacting bodies remains constant,providing no external force acts.
the rate of change of momentum of a body is directly proportional to the ecternal force cting on the body and takes place in direction of the force.
the total momentum of a system of interacting bodies remains constant,providing no external force acts.
the rate of change of momentum of a body is directly proportional to the ecternal force cting on the body and takes place in direction of the force.
问题解答：
我来补答展开全文阅读