SCIENCE! changes in temp?

[Hogger]

Quick science-y question... you have water at a temp of 40 Fahrenheit and hot water at 120 Fahrenheit. And they are in a room with constant temp of 80 Fahrenheit. What would reach the room temp first? the cooler getting warmer? or the warmer getting cooler?

[Enderman]

same

the rate of change depends only on the delta T

[vanished]

I believe it would be virtually identical since the main factor (the difference in temperature between the room and the water) is the same in both cases.  I mean, we could factor in the fact that specific heat capacity is not constant over a temperature range or that the fact one is cold and one is hot would create different free convection currents, but I think that's all super minor

[Hogger]

1 minute ago, Ryan_Vickers said:

I believe it would be virtually identical since the main factor (the difference in temperature between the room and the water) is the same in both cases.  I mean, we could factor in the fact that specific heat capacity is not constant over a temperature range or that the fact one is cold and one is hot would create different free convection currents, but I think that's all super minor

 

1 minute ago, Enderman said:

same

the rate of change depends only on the delta T

Interesting, I asked this bc i have cold subs and hot Indian food and i don't know what to eat first... lol

[Beskamir]

I think the warmer water would be faster since energy transfers are not 100% efficient and thus it would take more energy to warm up something than to cool it off. At least that's my prediction/hypothesis. It could very easily be that they both lose/gain energy at the same rate.

 

Anyways if you're interested in science stuff like this please use a logical measurement system...

[vanished]

Just now, Hogger said:

 

Interesting, I asked this bc i have cold subs and hot Indian food and i don't know what to eat first... lol

That totally changes the question.  The shape of the food, the substance (what it is made out of) and other things that are almost certainly going to be different between those two would all play a role.  I answered assuming everything not mentioned was kept the same between the two  

[Hogger]

This has been very interesting, I wish there was a hot Indian food heat change calculator somewhere!

[vanished]

Just now, Hogger said:

This has been very interesting, I wish there was a hot Indian food heat change calculator somewhere!

Well we can give some basic pointers.  First of all, the rate at which the temperature changes is a function of the heat capacity and the rate of heat transfer.  That is, how fast energy is entering or leaving the food, and how much energy the given substance has at any given temperature.

 

Now, the rate of heat transfer is going to be controlled primarily by the difference in temperature between your food and the room, but the thermal conductivity of the food, as well as the free convection currents setup by it sitting in a room of different temperature will also play a role.  Bring a fan into the question and now you have forced convection - much more effective (quicker) than just letting it sit there.

[Hogger]

1 minute ago, Ryan_Vickers said:

Well we can give some basic pointers.  First of all, the rate at which the temperature changes is a function of the heat capacity and the rate of heat transfer.  That is, how fast energy is entering or leaving the food, and how much energy the given substance has at any given temperature.

 

Now, the rate of heat transfer is going to be controlled primarily by the difference in temperature between your food and the room, but the thermal conductivity of the food, as well as the free convection currents setup by it sitting in a room of different temperature will also play a role.  Bring a fan into the question and now you have forced convection - much more effective (quicker) than just letting it sit there.

This is really cool, where did you learn all this?

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Just now, Hogger said:

This is really cool, where did you learn all this?

university taking chemical engineering

[Hogger]

1 minute ago, Ryan_Vickers said:

university taking chemical engineering

I had a feeling it was come kind of engineering... I'm still in high school, so this kind of stuff is like, revolutionary to me

 

[Narnash]

The hoter water will cool down first, if you don't cover the containers,caused by the evaporation of the waterwich cools it down. 

[vanished]

Just now, Narnash said:

The hoter water will cool down first, if you don't cover the containers,caused by the evaporation of the waterwich cools it down. 

Very good point, I hadn't considered that.  Yes, that's true, but it turns out he was actually talking about food, so that doesn't really apply after all

[Hogger]

Just now, Ryan_Vickers said:

Very good point, I hadn't considered that.  Yes, that's true, but it turns out he was actually talking about food, so that doesn't really apply after all

No worries, I finished my Indian food, subs are cold enough. My first world teenage problems are solved!!!

[Narnash]

2 minutes ago, Ryan_Vickers said:

Very good point, I hadn't considered that.  Yes, that's true, but it turns out he was actually talking about food, so that doesn't really apply after all

Yeah food would change the whole term we're talking about.

 

And if you talk about food of the same kind (suppose to be exactly the same) and you talk about cold and hot food and wich to eat first is pointless  

PS: as a hint stir and loosen the food than wait a moment and begin to eat from the side at first 

[vanished]

Just now, Narnash said:

Yeah food would change the whole term we're talking about.

I think subconsciously when I read the original question I just imagined two solid unchanging blocks of material rather than actually factoring in things like evaporation... something about the wording triggered that kind of simplified thinking we're trained to strive for.  I guess it becomes hard to turn off sometimes

[stijnweijters]

i wanted to say the same thing as Narnash (was just scrolling thru...) but since its food... Hot indian food is better hotter than colder... and subs are better colder than the hot of the indian... (but you know this already... was it nice?  )