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
 
        
             
        
        
        
CH3 is the empirical formula for the compound.
A sample of a compound is determined to have 1.17g of Carbon and 0.287 g of hydrogen. 
The number of atom or moles in the compound is
1.17 g C X  1 mol of C / 12.011 g C = 0.097411 mol of C.
0.287 g H x 1 mol of  H / 1 g H = 0.28474 mol H.
This compound contains 0.097411 mol of carbon and 0.28474 mol of Hydrogen.
So we can represent the compound with the formula C0.974H0.284.
Subscripts in formulas can be made into whole numbers by multiplying the smaller subscript by the larger subscript.
we can divide 0.284 by 0.0974. 
0.284 / 0.0974 = 3.
So here, Carbon is one and hydrogen is 3.
We can write the above formula as a CH3. 
Hence the empirical formula for the sample compound is CH3.
For a detailed study of the empirical formula refer given link brainly.com/question/13058832.
#SPJ1. 
 
        
             
        
        
        
part 1 : the final volume : 1.404 L
part 2 : the initial concentration : 4.06 M
<h3>Further explanation
</h3>
Dilution is the process of adding a solvent to get a more dilute solution.
The moles(n) before and after dilution are the same.
Can be formulated :
M₁V₁=M₂V₂
M₁ = Molarity of the solution before dilution  
V₁ = volume of the solution before dilution  
M₂ = Molarity of the solution after dilution  
V₂ = Molarity volume of the solution after dilution
part 1 :
M₁=44.8%
V₁=0.73 L
M₂=23.3%

part 2 :
V₁=739 ml=0.739 L
V₂=1.5 L
M₂=2

 
        
             
        
        
        
Answer:
a motor that requires no energy input once it is running