dont use that link its bad
 
        
             
        
        
        
Answer:
 162.7miles/hr
Explanation:
Given parameters: 
Distance covered by the train  = 813.5miles 
Time taken  = 5hours 
Unknown: 
Speed of the train  = ? 
Solution: 
Speed is a physical quantity. 
 It is mathematically expressed as;
       Speed  =  
 
So, input parameters and solve;
    Speed  =  = 162.7miles/hr
  = 162.7miles/hr
 
        
             
        
        
        
The subatomic particles that identifies an element and also represents its atomic number would be A. The number of protons.