Why does metal feel colder than the surrounding air temperature?

Answer 1

it conducts here faster and better. When your body temperature is higher than the metal, your heat transferred to the metal and quickly spread to the whole metal. When you have a large piece of metal, you will need to transfer a lot of heat to raise it's temperature as the same level as your body. It becomes a heat sink, and you will always feel that piece of metal is cooler.

Answer 2

This has to do with heat capacity. The air can only hold a relatively small amount of energy/volume compared to metal and so it only takes a small amount from you as it attempts to reach equilibrium. Metal has a high heat capacity and can absorb a lot more energy (heat) before it increases in temperature. This works the other way around as well. Think of what happens when you open an oven that has been heated up to say 350 degrees. The air inside the oven is at 350 degrees but when you put your hands into it it doesn't burn you, however if you grabbed one of the metal racks also at 350 degrees it would burn you immediately. The metal holds a lot more energy/volume (heat) and can transfer it to you quickly.

Answer 3

Metal is in a frozen state! That is one of the reasons it feels colder than the surrounding air temperature.

Because we are so water oriented, we only think of ice as being an element in a frozen state.

Look at the element/metal Mercury - it has a lower freezing temperature than water. That is why we experience it as a liquid and why it is used in thermometers.

Answer 4

These answers are a mess! My knee-jerk answer is that Scott was correct and the high thermal conductivity of metals is the reason.

This is pretty close to the correct answer, because it is the conductivity that is so much bigger for metals than other materials. The conductivity of aluminum is about 2 Watt/(cm-deg). Iron or brass is about 0.8 W/(cm-K). For plastic it is about 0.002 Watt/(cm-K). And for air it is about 0.00025 W/(cm-K) which is really small.

But here is the correct answer: How far does heat travel in a solid in time t?

Answer: D = (t*k/6*rho*cp)^0.5 where k is therm cond. & cp is the specific heat per unit mass. rho*cp is the specific heat per unit volume.

How much heat is delivered to the solid in time t?

Answer: Q = A*D*rho*cp where A is an arbitrary contact area we can ignore. So substituting in for D we have

Q = (t*k*rho*cp/6)^0.5

So the answer is that the product of thermal conductivity and volumetric heat capacity is the key physical property, k*rho*cp.

Finally, why do metals have such a high thermal conductivity??
The free (to move around inside the solid) electrons of metals carry electrical current AND heat extremely well. This close relationship between heat and electrical conductivity is called the Wiedemann-Franz Law.

Answer 5

This is all about thermal conductivity. If air and a piece of metal are at 70 deg F and your body temp is at 98 deg F, the metal is going to feel cooler because the metal has a higher thermal conductivity.

Answer 6

Metals have a lower specific heat capacity than other materials. Thus they conduct heat much faster. Air is an insulator. You breathe in it but it doesn't take away your body heat too much. Whereas metals conduct very well so when you touch them,they take away the heat from your body making them seem cold. So metals are colder than air.

Answer 7

It can absorb heat much faster than air, so draws it away from your skin. But, I don't know why.

Of course, metal left out in the sun eventually gets to feel much hotter than the surrounding air. I think the two are linked.

Answer 8

Casting a knife is probable no longer an incredible concept in case you will use the sting, if its for looks and you dont choose it to hold an area, you need to use moist sand. what steel are you planing to apply as all metals have a distinctive temp that they soften at?

Answer 9

This should be of some help to you. It was the best short answer I could find.

http://www.me.gatech.edu/jonathan.colton/me4210/effusivity.pdf