物体的浮沉情况，常用“漂浮”、“上浮”、“悬浮”和“下沉”来描述．用运动和力的知识可以帮助我们理解这些词的物理意义．漂浮是一平衡状态．这时物体受到的浮力等于它的重力，这两个力方向相反，是一对平衡力，因此，物体保持静止．上浮是一运动过程．如将一木块压入水中 The floating condition of an object is often described as “floating,” “floating,” “floating,” and “sinking.” Using knowledge of movement and force can help us understand the physical meaning of these words. Floating is a balanced state. At this time, the buoyancy of the object is equal to its gravity. The two forces are in the opposite direction. It is a pair of balance forces. Therefore, the object remains stationary. Floating is a movement process. If a piece of wood is pressed into water