气流投篮

       观众将气球放置在出风口上，慢慢调整风口的方向，就可以将气球送往篮筐。由伯努力原理可知，在气流的中心流速大于四周流速，压强小于四周压强，这使得气球只能沿气流中心指定方向运动。

The air stream throws balloon into basket

        The spectator places the balloon at the air outlet, adjust the orientation of air outlet slowly and throw the balloon into the basket. From Bernoulli’s law we know the velocity at the center of the air stream is larger than that around and the pressure at the center is less than that around. So it makes the balloon move only along the designated direction of the air stream center.