In science class...

[Externet]

A zillion years ago, about 8th grade in school, the teacher was demonstrating something and put water in a vessel to boil on a bunsen flame. He placed a glass/mercury thermometer inside to show the reading.

 

I was the only one who warned the teacher that could not the correct way to measure the water temperature, as the thermometer bulb was contacting the bottom of the vessel and would read higher than real water temperature.

 

Then he held the thermometer by hand suspended, touching only the water with an embarrassed red face.

 

Now am thinking if I was wrong. Would the vessel be at the same temperature as the water contacting in it, or would the vessel be hotter as I pointed because it was contacting the flame; or somewhere in between (Which would still be a higher reading) ?

Edited January 21, 2013 by Externet

[Phi for All]

It would seem that if the vessel wasn't hotter than the water, transferring the heat of the flame beneath it, the water wouldn't increase in temperature.

[evansste]

I agree with @Phi for All. If the pot was a "perfect" conductor of heat, then both the water and the pot would always be the same temperature. This is because the pot would relay its heat just as quickly as it obtained it. But in reality, the pot must get hot before the water on the other side gets hot. Therefore, the pot would be at a higher temperature. Once the burner is turned off, it makes sense that both the water and the pot would eventually equalize and become the same temperature.

 

It helps to remember that the temperature of an object is really just a macroscopic, or collective, measurement of the kinetic energy of the atoms (or molecules) that make up that object. When an object is hot, its molecules are vibrating faster than when it is cold. Heat is transferred when these molecules collide with neighboring molecules of anything that may be touching it, causing those molecules to vibrate more quickly.