I would say your answer is B- Some of the chemical energy from the batteries is converted into heat energy. 
        
             
        
        
        
The answer is C , you’re welcome
        
             
        
        
        
The strong nuclear force holds the nucleus of an atom together.  
Somehow, it overcomes the electrical force of repulsion between protons in the nucleus, which all have the same charge but still stay close together somehow. (b) 
 
        
                    
             
        
        
        
Answer:
|x| = √53
Explanation:
We are told that the vector starts at the point (0.0) and ends at (2,-7) .
Thus, magnitude of displacement is;
|x| = √(((-7) - 0)² + (2 - 0)²)
|x| = √(49 + 4)
|x| = √53