摘 要：求解轨道对物体的弹力是一类常见问题，其中涉及公式F=ma ，选

摘 要：求解轨道对物体的弹力是一类常见问题，其中涉及公式F=ma ，选择恰当的参考系，可以使求解过程简明、清晰。

結果 (英文) 1:

Summary: solving the stretch of track on object is a class of frequently asked questions, involving the formula f = Ma, selecting the appropriate reference systems, can make the solution process simple and clear.

結果 (英文) 2:

Abstract: Solving rail stretch is a class of objects common problems, which involves the equation F = ma, choose the appropriate reference system, you can make the solution process concise, clear.

結果 (英文) 3:

Abstract: the elastic solution trajectory on the object is a common problem, which involves the formula F=ma, select the appropriate reference system, can make the solving process is concise, clear.