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          按照圖的要求畫出滑輪組的繞繩方法(不計滑輪重、繩重及摩擦)
          			
          


			
          

		
          
		
		
	
          
		
          
			
          
				
          
				

          試題分析：動滑輪被幾根繩子承擔，拉力就是物體和動滑輪總重的幾分之一（1）F=，由4段繩子承擔滑輪的重；（2）F=，由5段繩子承擔滑輪的重．

          點評：滑輪組設計原則可歸納為：奇動偶定；一動配一定，偶數(shù)減一定，變向加一定．
          				
          
							
          
			
          
			
          
			
			
          
		
          
	
          

		
          

		





			
          
		
          
		
				
          
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