Answer:
d
Explanation:
d because a b c are energy equation not work
 
        
             
        
        
        
Answer:
a) the mass of the second car = 28000 kg
b) the amount of kinetic energy that was lost in the collision = 
Explanation:
Given that:
mass of the train car  = 6300 kg
 = 6300 kg 
speed of the train car  = 12.0 m/s
 = 12.0 m/s
mass of the second moving car  = ???
 = ???
speed of the second moving car  = 2.2 m/s
 = 2.2 m/s
After strike; 
they both move with a speed  = 4.00 m/s
 = 4.00 m/s
a)
Using the conservation of momentum :







b)
To determine the amount of kinetic energy that was lost in the collision;
we will need to find the difference between the kinetic energy before the collision and after the collision;
i.e







 
Now;  the  kinetic energy that was lost in the collision is calculated as follows:




 
        
             
        
        
        
By definition we have that the force for time is equal to the product of the mass for the change in speed.
 We have then that
 F * (delta t) = m * (delta v)
 Clearing the mass
 m = (F * (delta t)) / (delta v)
 Substituting the values
 m = ((3.00) * (4.00)) / (7.50-6.00) = 8
 answer
 The mass of the moving object is 8Kg