多数男孩都喜欢玩陀螺。说来也怪,这种圆锥形的东西,转得越快它越稳,一旦停止转动就会立刻歪倒。如果仔细看看,我们就会发现弹丸的旋转与陀螺的运动是一样的。陀螺有一定重量,当把它竖在平地上时,因为重力和支点的作用力组成了一个力偶,所以只要稍有倾斜就会翻倒。 Most boys like to play gyro. Strange to say, this conical things, the faster the faster it becomes more stable, once stopped, it will immediately fall down. If we take a closer look, we will find that the projectile's rotation is the same as that of the gyro. The gyro has a certain weight. When it is erected on the ground, the force of gravity and fulcrum make up a couple, so it tilts when tilted slightly.