by bolt » 30/05/06, 15:26
hello tryf
you can see in tables (wiki or other) the difference between thermal mass capacity, which of course must be transformed into thermal volume capacity to account for it at the same time as we see
otherwise we are deceived by the same object in different matters
(aluminum is light)
et thermal conductivity
alu: 900 joule / (kg of degree) ... x 2,7 (kg / liter) = 3333 j / (liter of degree) conductivity = 237 watt / (degree m)
copper: 385 d / (kg) ... x 8,6 = 3388 j / (l. °) conductivity = 401w / (m. °)
iron: 444 d / (kg) ... x 7,8 = 3463 j / (l. °) conductivity = 46 w / (m. °)
stainless steel:? = ? conductivity = 26
the "same" piece of aluminum, copper or iron, at the same temperature contains roughly the same amount of heat (numbers in red)
It would only be the thermal conductivity that changes a lot
copper: 1,7 times more than aluminum
8,7 times more than iron
15,4 times more than stainless steel (18% chromium; 8% nickel)
For the sensations,
when you take a piece in your hand: between aluminum and iron, for example, the piece of iron conducts heat much less quickly than aluminum, the surface of the iron can descend much more quickly in T °, during that it transmits part of its heat to the hand (therefore tenable at that time), then it takes more time for the heat (volume) to leave the interior of the room to go towards the hand
in other words when you take an iron piece at 50 ° C, it is very likely that you will actually feel it: say 40 ° C
But for aluminum and even less copper, the edge of the metal will remain almost at 50 ° C, as long as the interior has not dropped to T °
bolt
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