Question for Physics people

[Dr Kenneth Noisewater 0]

Why doesn't tin foil get hot in the oven?

 

I've just burnt my thumb on the baking tray and my finger on the pyrex dish. But the tin foil isn't much above room temp?? I thought metals were good heat conductors? Someone explain the science part for me.

[peasepud 59]

The higher the specific heat capacity, the more energy that is require to make the objects temperature rise. Since aluminum has a very low specific heat, it only takes a little bit of energy to heat it up. But this works both ways. It also only has to release a small amount of energy to cool down. Therefore, it cools very quickly and so by the time you grab it out of the oven, it only feels mildly warm.

[Dr Kenneth Noisewater 0]

I seeeee. So it does get hot, I'm just not quick enough.

[peasepud 59]

Yup, if you sit in the oven with the foil in your hand you'll find it gets hot.

[Rob W 0]

volume also counts - as its v v thin it can't retain much heat - it very quickly adjusts to the ambient temperature

[Craig 6682]

The higher the specific heat capacity, the more energy that is require to make the objects temperature rise. Since aluminum has a very low specific heat, it only takes a little bit of energy to heat it up. But this works both ways. It also only has to release a small amount of energy to cool down. Therefore, it cools very quickly and so by the time you grab it out of the oven, it only feels mildly warm.

8083[/snapback]

 

 

www.ask.co.uk??

[peasepud 59]

The higher the specific heat capacity, the more energy that is require to make the objects temperature rise. Since aluminum has a very low specific heat, it only takes a little bit of energy to heat it up. But this works both ways. It also only has to release a small amount of energy to cool down. Therefore, it cools very quickly and so by the time you grab it out of the oven, it only feels mildly warm.

8083[/snapback]

 

 

www.ask.co.uk??

8123[/snapback]

 

 

Sceptic

[luckypierre 0]

sort of right. heat capacity has a lot to do with it but if you shoved a bit of aluminium in the oven the same shape/mass as your grill you'd burn your hand on it the same. Robs more or loss got it with the volume but its down to the relative surface area. Its the same reason why radiators are shaped the way the are. The greater the surface area the greater the heat loss and aluminum foil is basically all surface area so the heat loss is almost instantaneous. Theres other stuff like heat transfer coeficients that come into play but that would be trying to hard to remember the stuff I learnt at uni and Ive spent too much time forgetting that..

[Craig 6682]

The higher the specific heat capacity, the more energy that is require to make the objects temperature rise. Since aluminum has a very low specific heat, it only takes a little bit of energy to heat it up. But this works both ways. It also only has to release a small amount of energy to cool down. Therefore, it cools very quickly and so by the time you grab it out of the oven, it only feels mildly warm.

8083[/snapback]

 

 

www.ask.co.uk??

8123[/snapback]

 

 

Sceptic

8136[/snapback]

 

You're a tax man, I know you know fuck all about specific heat capacity....

 

It's 10 years since I did A-Level Physics and I've having a job remembering it!

[Jusoda Kid 1]

The higher the specific heat capacity, the more energy that is require to make the objects temperature rise. Since aluminum has a very low specific heat, it only takes a little bit of energy to heat it up. But this works both ways. It also only has to release a small amount of energy to cool down. Therefore, it cools very quickly and so by the time you grab it out of the oven, it only feels mildly warm.

8083[/snapback]

 

 

www.ask.co.uk??

8123[/snapback]

 

 

Sceptic

8136[/snapback]

 

You're a tax man, I know you know fuck all about specific heat capacity....

 

It's 10 years since I did A-Level Physics and I've having a job remembering it!

8245[/snapback]

 

While were on Why don't fly's burn their feet when they land on a lightbulb? I know it's an old one but why don't they?

[Craig 6682]

Absence of nerves in their feet?

[Rob W 0]

sort of right. heat capacity has a lot to do with it but if you shoved a bit of aluminium in the oven the same shape/mass as your grill you'd burn your hand on it the same. Robs more or loss got it with the volume but its down to the relative surface area. Its the same reason why radiators are shaped the way the are. The greater the surface area the greater the heat loss and aluminum foil is basically all surface area so the heat loss is almost instantaneous. Theres other stuff like heat transfer coeficients that come into play but that would be trying to hard to remember the stuff I learnt at uni and Ive spent too much time forgetting that..

8149[/snapback]

 

this is why elephants occasionaly burst into flames.....................

the shape is wrong.............