Andy Hall wrote:

The energy equation is pretty simple. We know that there is not an
issue of the heat being transferred into the water since it has nowhere
else to go. Therefore if one takes a given amount of water in both
cases and heats it from temperature T to 100 then the energy used in the
time difference would account for the difference in loss.

I guess one possibility is that the stainless was lying about the power
rating...


It's not possible that there was less water in the plastic kettle?
These tend to be jugs whereas the metal ones are usually more
traditional kettle shaped. Hmm.... thinks difference in surface area
of short squat cylinder vs. tall one?

No, it was a jug one, a little like this (but without the windows)
http://www.comet.co.uk/cometbrowse/p....do?sku=272825


As for the toaster, I think it's harder to work out. Here the heat
transferred to the bread would depend on what's behind the element
(insulation and reflection of some kind?) and proximity of element to
bread.

The toaster was bad for different reasons - it seemed incapable to
irradiating the bread evenly, so you always ended up with some burnt
bits and some untoasted bits. I think that was just poor design, and not
related to the casing material.


--
Grunff