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				           		A zero friction coefficient means that no shear forces will develop and the contact surfaces are free to slide.
						        										 	
						        					            	 零摩擦系数意味着没有剪力发生,且接触面自由滑动。
								    				            	 youdao 
- 
				           		A zero friction coefficient means that no shear forces will develop and the contact surfaces are free to slide.
						        										 	
						        					            	 零摩擦系数意味着没有剪力发生,且接触面自由滑动。
								    				            	 youdao