Whose Porrige should have been coolest?

You need to be more specific about the bowls.

All made from the same type of china, and the same shape (a bit like the bottom third of our planet only hollow. one 4" dia one 5" one 6".

Unless the bowls had particularly conductive (thermally) bases, the largest bowl would have cooled fastest. However, the smallest bowl, being baby bear's bowl, is likely to have been cooler to start with (so as not to burn baby bear).

And which was dished out first.

Is the thickness proportional to the diameter, or the same in all three?

Unless you intend some trick, then the baby's will.

I agree with the -smallest- bowl.

This assumes that heat loss is uniform over the entire body surface. This won't be the case. Heat loss will be much, much higher from the surface of the porridge than from the bowl. In fact, most of the heat loss will be evaporative, at least during the first few minutes. As such, the largest bowl will cool fastest, despite the smaller surface:volume ratio.

But wouldn't the evaporative losses still be related to x squared, whilst the available energy is x cubed? It's just an alternative form of surface loss.

Christian.

I think this is wrong. Daddy's porrisge has greatest surface area, so loses most joules per minute, but it also has a temp drop of less deg C per joule, since there is more porridge there. Quite simply it comes down to the area/volume ratio. In both exposed porridge area and bowl area, daddys porridge has least area per voume, baby's greatest.

If and only if all other things are equal, babys cools fastest. In the real world of course, other things are more often not equal, eg baby's was probably served at a lower temp to start with..

NT

It depends. Were the bowl U values compliant with BRs? Was the porridge old fashioned porridge, ready brek, rice porridge, or wheat porridge? Were the portions subject to portion control? Was the porridge served litigiously hot? Or had it passed a care range valve designed to limit it to 43C?

NT

I suggest Daddy bear's was warmed on "full power" for longer. - Although thinking about it microwave ovens were probably not around back then.

- clearly the witness statement from Goldilocks, does not specify the heating method, and therefore would not stand up in court.

Of course Mummy bear may have added some milk to Baby bear's bowl before serving.

Interestingly, the version at :-

Was the porridge supplied by Ye Olde "Ronald McDonald", and came with a label - "Careful Porridge may be hot"..

In fact, reading the link above, it says that Daddy bear's soup was too hot with Pepper. - aha, so it was "spicy" hot, rather than "heat" hot after all.

How many bears in the real world make porridge??

And in a plastic bowl in case he chucks the lot across the room.

MBQ

Surely that should be "Caution, porridge may be hot after heating"

Thanks for interesting replies (i'm sure there'll be more!) I like some others was working on the basis that the largest suface area of porridge would give the quickest cooling.

OK, you've two bowls of hot water in identical situations. One is covered with large soapy bubbles (bubble bath). Which will cool quicker? The surface area of the bubbles is larger than that of the surface area of the non-bubbly water.

The bubbles will act as insulation, making the soup stay hot for longer. Think of a hot water cylinder, one covered in insulation. The insulated one has a greater surface area, but I bet it stays hot longer!

Christian.