《小问题》栏欢迎来稿出题（请自拟题目或注明题目来源），题目及解答请寄清华大学工程力学系《小问题》组，采用后将致薄酬２９０．假定我们想设计一个“不倒翁”，其底部轮廓线在结体坐标Ｂ－ｘｙ中为ｙ＝ａｘ２，（ａ＞０），顶部暂不考虑，重心Ｃ在ｙ轴上．为了让“不... “Small problems” column welcome contributions to the title (please self-question or indicate the source of the title), questions and answers, please send Tsinghua University, Department of Engineering Mechanics “small problems” group, will result in poor pay 290. Suppose we want to design a “tumbler” whose bottom contour is y = ax2 in the B-xy coordinates (a> 0), the top is not considered, and the center of gravity C is on the y-axis. In order to make "no ...