题目.如图1所示,A、B两球质量相等,A球用不能伸长的轻绳系于O点,B球用轻弹簧系于O′点,O与O′点在同一水平面上,分别将A、B球拉到与悬点等高处,使绳与轻弹簧均处于水平,弹簧处于自然 Title, as shown in Figure 1, A, B two balls of equal mass, A ball with light rope can not be stretched at O ​​point, B ball with light spring at O ​​’point, O and O’ point in the same level , Respectively, A and B ball pulled to the hanging point and other places, so that the rope and the light spring are at the level of the spring in the natural