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seen Jan 7 '12 at 22:44

Jan
7
awarded  Student
Jan
7
comment Certain material heating water in a recipient
While learning Physics (thanks to Khanacademy, and thanks to this place too!) I did many problems related with this one, applying the formula I posted above (if I don't remember bad, calorimeter-related). And I think the same formula applies here, but since the heat energy transfered is being pushed (or let's say, "accelerated") thanks to the fire wood, my formula lost some of its sense. Well, it's just... maybe I'm completely wrong, but never did an exact problem like this and learning Physics from scratch has this kind of things, ah? :)
Jan
7
awarded  Editor
Jan
7
comment Certain material heating water in a recipient
... and it's done! Thanks David. I felt guilty last time because of that and didn't want to make the same mistake again. I'm trying to learn, that's why I don't want the final answer, but how to continue resolving my problem, since I'm unable to plug all the data in the formula - so probably I'm missing something as I said.
Jan
7
revised Certain material heating water in a recipient
Changing the text as suggested
Jan
7
comment Certain material heating water in a recipient
Hi David! Well, it's not actual homework but let's take it like that. I didn't posted the full problem since I didn't wanted an answer. What the problem says is we have 85 liters of water at 7ºC in an iron pot of 29kg. We want the water to be at 86ºC. The temperature of the iron pot is 12ºC. The water is heated by fire wood (65% of the thermal energy is wasted in combustion), and has a heating value of 12 MJ/kg. We need to determine the amount of wood needed to heat the water. And I don't know how I should understand this with the formula I posted...
Jan
7
asked Certain material heating water in a recipient