大家都熟悉直升机 ,知道它能悬停、前飞、侧飞、后飞、垂直起飞和降落 .但是知道它为什么能实现这些动作吗 ?很显然这与力学知识有关 .飞机的发明 ,使人们在普遍受益的情况下又产生了新的不满足 .飞机起飞需要滑跑 ,需要修建相应的跑道和机场 .这就带来了诸多不便 .于是有人开 Everyone is familiar with the helicopter and knows that it can hover, fly forward, fly sideways, fly backwards, take off and land vertically. But does it know why it can achieve these movements? Obviously this is related to the knowledge of mechanics. The invention of the aircraft made people With the general benefit, new dissatisfaction was created. The plane took off and needed to run. It needed to build the corresponding runway and airport. This caused a lot of inconvenience. So someone opened it.