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        A 1050 kg car moving south at 10.0 m/s collides with a 2650 kg car moving north.  
The cars stick together and move as a unit after the collision at a velocity of 5.16 m/s to the north.  
Find the velocity of the 2650 kg car before the collision 
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This is a conservation of momentum problem where  
momentum = mass*velocity (MV) 
 
The north-bound car will have more momentum than 
The south-bound car. 
 
Given: 
 
1,050*10.0 = 10,500 kg m/s (going south) 
2,650*V      = momentum of car going north 
(1050+2650)*(-5.16) = combined momentum going north 
 
HENCE: 
 
10500 –2650*V = (1050+2650)*-5.16 
 
-2560V = -19092-10500 
 
-2560V = -29592 
 
V = -29592/-2560 
 
V = 11.56 m/s
     
     
    
    
    
    
    
    
  
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