笔者在多年从事初中物理教学实践中发现,悬浮实验一直是教学的难点和盲区,尽管不少文章从不同角度阐明自己的做法,从中看到悬浮确实可以实现,例如,鸡蛋在浓盐水中悬浮,但是操作起来仍感不易。笔者在数年前采用先配制浓盐水的方法,使鸡蛋漂浮后再缓慢加入清水,逐步稀释上层盐水,从而实现悬浮。因为盐水密度呈现自上而下逐渐增大的阶梯式分布,所以当鸡蛋下沉运动到其平均密度等于所处位置周围盐水的密度时恰好悬浮。 After years of practice in junior middle school physics teaching, the author found that suspension experiment has always been a difficult and deadly area for teaching. Although many articles clarify his own practice from different perspectives, we can see that suspension can indeed be achieved. For example, eggs are suspended in concentrated brine, However, the operation is still not easy. A few years ago, I used to prepare concentrated brine first method, so that the eggs floating slowly after adding water, and gradually dilute the upper brine, so as to achieve suspension. Because the brine density presents a stepped distribution that increases from top to bottom, the eggs just float when they sink to an average density equal to the density of brine around the location.