After some time of uninterrupted fall, the body is moving so rapidly that the drag of the air is as great as the weight of the body, so that there is no acceleration.
After some time of uninterrupted fall, the body is moving so rapidly that the drag of the air is as great as the weight of the body, so that there is no acceleration.
经过一些时间的自由降落后，落体运动得很快，以至空气拽力（阻力）与落体的重量相等，于是就没有加速度了。