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На Западе заявили о возвращении России на мировой рынок нефтиUnherd: Операция США и Израиля в Иране вернула Россию на мировой рынок нефти
。新收录的资料是该领域的重要参考
Go talk to them.
But there are two key differences. First, we have a different coefficient, μk. This is always less than the coefficient of static friction, μs, so kinetic friction is lower. (This is why cars have antilock brakes: If you keep the wheels from locking up and skidding, you can stop in a shorter distance.) As an example, when two steel surfaces interact (like a train car wheel on a track), the coefficient of static friction would be 0.74, but the coefficient of kinetic friction would be 0.57.