haha That is homework! And of course I am no physics teacher so I cab be radically wrong!
I just felt very very
Yes, you are very, very radically wrong. I was on the ferry from Tanah Merah (near Changi Airport) on my way to play golf in Batam. There were 4 Koreans with me on the way to play golf as well. We were riding on the top deck, under open skies.
We watched an SQ 777 take off from Changi and the Koreans were talking about it. I mentioned that it had about 90,000 lbs of thrust per engine, or 180,000 lbs total. A few minutes an SQ 747-400 took off. We watched it and they asked my 'how much'. About 60,000 lbs and engine or 240,000 total, I said. Then a Quantas A380 took off and naturally the question arose again. I replied that each engine was around 80,000 lbs of thrust for 320,000 total.
Then they wanted to know how much 'power' that was. I've read lots about power/thrust and lack of direct relationship and I could not answer them. But yesterday it occurred to me that a satisfactory answer could be obtained in the form a the laws of motion. What I needed was some numbers to plug into them.
So, -2 for you... not homework, an attempt to answer a question for the next set of Korean golfers that ride over to Batam.
Simply put, jet engines are thrust producing machines, they don't give us power for fuel. You cannot compare them.
I am assuming you read my post wherein I stated at the beginning
"So, I think this question is not answered by trying to relate thrust directly (which as the article above and several others imply, is essentially a fruitless endeavor) ..."? You see, I am well aware that there is no simple relationship between thrust and power. You might try Aerospaceweb.org | Ask Us - Convert Thrust to Horsepower fopr a decent write up on some of the difficulties.
But the remainder of your quote is simply not correct. Of course, engines give us power for fuel. It is the power that creates the thrust. It's just not a nice neat relationship like converting miles per hour to furlongs per fortnight. This is why I chose to use the simple equations of motion with constant acceleration to model how much power it takes to get a 747-400 to the point that it will fly.
And of course I am no physics teacher
I get that. ALL I want to do is compute how much power it takes to roll an 875,000 lb airplane from V0 to Vr (whatever that is). If it were a textbook physics problem it could just as easily be a big block of lead being accelerated down a frictionless plane.
To do this I must know at least 2 or 3 variables (with some reasonable guestimate of temperature (standard day plus 30F?), wind (none?) and other factors that actually go into power settings, rollout, etc.
The point of this whole exercise is not to try to relate power to thrust but to have some 'fun' talking points about how cool it is to fly big iron.
Cheers.