An imbalance between electrical charges
        
             
        
        
        
In a displacement versus time graph, the slope of the line at any point on the graph indicates the <em>magnitude of velocity</em>.  
(It can't indicate velocity completely, because the graph shows nothing about the direction of the motion.)
 
        
                    
             
        
        
        
Having different densities being swirled rapidly will cause sedimentation. Sedimentation is the segmentation of the mixture creating layers of particles of these different densities. The process of rapid swirling is called differential centrifugation. An example use of this method is separation human blood into, red, platelet and white blood cells.
        
             
        
        
        
Answer:
50.4 N
Explanation:
Q1 = Q 
Q2 = 4 Q
Distance = d 
The force is given by 

 .... (1)
    .... (1) 
Now, 
Q3 = 2 Q 
Q4 = 7 Q 
distance = d/3 

 .... (2)
   .... (2) 
Divide equation (2) by equation (1), we get 
F' / 1.60 = 126 / 4 
F' = 50.4 N 
Thus, the force is 50.4 N.