From Newsgroup: rec.puzzles

Also a long time (50 years) ago I would read New Scientist magazine. The inside of the back cover contained readers' letters, questions and
puzzles. One concerned a kitchen sink mixer-tap (faucet) and the
temperature of the water exiting the tap.

The correspondent noted that if the hot tap was left running, and the cold
tap turned on a later time, then the temperature of the water exiting the
tap initially appeared to increase, before decreasing.

The following edition included some responses, but, if I recall correctly, they all suggested the increase in temperature was not real and it was all
to do with perception.

Although I haven't done any calculations, noting that our kitchen top comprised a hollow outer metal body and an inner copper pipe, of smaller diameter, the two flows mixing at the outlet, I can see why the effect
would be real. I'd like to set the record straight...
--
David Entwistle
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From Newsgroup: rec.puzzles

On Mon, 4 May 2026 12:35:37 -0000 (UTC), David Entwistle wrote:

Although I haven't done any calculations, noting that our kitchen top comprised

kitchen tap...
--
David Entwistle
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