“动态平衡”问题是指通过控制某些物理量使物体的状态发生缓慢变化,而在这过程中物体又始终处于一系列的平衡状态.解决这类问题的难点是“动态平衡”过程中变化量与不变量关系的挖掘.下面就2012年江苏省南京、盐城两市高三物理联考中一道动态平衡的检测题作一些思考.题目:如图1所示,xpy为直角支架,杆xp、绳ao均水平,绳bo与水平方向夹角为60°.如果在竖直平面内使支架沿顺时针缓慢转动至杆yp水平,始终保持ao、bo两绳间的夹角120°不变.在转动过程中,设绳 The problem of “homeostasis” refers to the slow change of the state of an object by controlling certain physical quantities, and in the process, the object is always in a series of equilibrium states. The difficulty in solving this kind of problem is that the “homeostasis” The process of change and invariant mining.Following the following 2012 Jiangsu Nanjing, Yancheng two physical high school entrance examination in a dynamic balance of test questions for some thinking.As shown in Figure 1, xpy is a right angle bracket, The bar xp, the rope ao are level, the angle between the rope bo and the horizontal direction is 60 ° .If the bracket in the vertical plane to slowly rotate the lever yp level, always maintain ao, bo angle between the two ropes 120 ° In the process of rotation, set the rope