This friction tends to slow the speed of winds, making them far less efficient at dispersing pollutants.
这种摩擦往往会减慢风的速度，使它们吹散污染物的效率大大降低。
2
The falling object, after traveling a certain distance through the air reaches a final speed, or "terminal velocity," because the object's friction with the air slows the fall.
物体在下落一定距离后由于空气阻力都会达到一个终极速度。
3
For tapered roller large end and sliding friction between the inner wall, the speed limit is often lower than the same size cylindrical roller bearings.