Now, see that less-than-or-equal sign? This says μsN is the maximum static friction force in a given situation. If you push the book with a force of 1 newton, the frictional force will be 1 newton. Double the pushing force and the frictional force also doubles. It does whatever it has to in order to keep the two surfaces stationary—up to a point. If you keep pushing harder, your applied force will eventually exceed μsN and the book will start to slide. At that point, kinetic friction kicks in.
传统的全球AI枢纽，如硅谷、北京、深圳，其核心优势在于顶尖人才的聚集、风险资本的澎湃与初创生态的繁荣，如今，新一代的枢纽正在崛起，其核心竞争力是非常朴实的：
，更多细节参见快连下载
This week's leading scientific developments are examined by Nature's editorial team.
dominates. Nonlinear coordinate transforms (polar to rectangular, or gamma