纠正初中物理“孔明灯”的不准确描述

Revising the Inaccurate Description of Sky Lantern in Middle School Physics

上海科学技术出版社初中八年级《物理》教材用浮力和密度描述了"孔明灯"升空原理和过程。实际制作放飞过程中发现当孔明灯所受重力大于浮力时孔明灯依然能够升空。此实验证明了阿基米德原理不适用于孔明灯,初中物理用浮力和密度来描述孔明灯的升空原理是不正确的;验证了孔明灯升空原因是灯罩内气流运动形成的向上冲击力;采用配重方式测量了上升力。

Published in the Eighth Grade Junior Physics by Shanghai Science and Technology Press, the buoyant force and the density have been used to describe the theory of the floating process for the Sky Lantern. However, in real-world experiment, Sky Lantern could still float even when the gravity force was more than the buoyant force. This indicated that somehow the Archimedes Law wouldn＇t apply on this phenomenon - using buoyant force and density to define the floating process may not be 100% accurate. It also demonstrated that the rising force gen- erated by the hot air flow inside the lantern. In the experiment, the maximum rising force could be measured by gradually in- creasing the gravity force.