Hey, just curious... when you say that it takes a specific amount of joules to heat water, why is the time variable, surface area of the body of water and surrounding temperature ignored? It seems so weird to me to hear that it takes a fixed amount of energy to heat water from temperature A to temperature B. I feel there are so many more variables involved.

Are you just ignoring variables for the sake of being able to give an answer? Seems to me like a classic scenario of "they taught me to ignore these variables in physics class". Or am I wrong? I'm very curious. I was trying to solve it logically but it wasn't possible due to missing variables. I have no clue about thermodynamics.

[–] prime_number_314159@lemmy.world 3 points 10 months ago (1 children)

I'm ignoring many factors for the sake of being able to answer. There are some kinds of heating, especially using burning fuels that are nearly 100% efficient, but we don't know why it needs to get to that temperature, or how long it needs to stay that hot - so even if the transfer of heat is 100% efficient, this computation may underestimate the actual needs.

[–] platypus_plumba@lemmy.world 1 points 10 months ago* (last edited 10 months ago)

Ah, alright, I was feeling dumb because the formulas made no sense to me but it is just a model providing a practical approximation. Thanks!