This is a follow-up based on a question posted here. I updated my initial question but came to the conclusion that a new post might be more manageable. For bibliographic reference(s) and/or getting a copy please refer to the linked question. Be that as it may, this is my current issue:
Having had some time at hand, I went back to the book. The solution of the problem set above continues like this:
Assuming the weight of the power plant and its cars to be 8.lbs/Hp. and the weight of the fuel and the fuel system to be .6 lb. per horsepower hour, the total weight of power plant, fuel system and fuel is
[8 + ( .6 x 60 ) ] Hp. = 44 (Hp.)
combining this with the military load,
15,000 + 44 (Hp.) = .357
However, I cannot make heads or tails of the next part
Combining equations (1) and (2)
My question is how did the author arrive at equation (3)? Where does the value
48D(2/3) come from and how were these formulae combined.
When using the previously computed value of .0357 for D, I am not getting the result of 42,000.
Apart from the "actual" math involved, I fail to see the meaning of the components involved in equation (3):
Could someone help me out here and maybe translate that formula into English sentences?