By Anonimski - Own work, CC BY-SA 3.0, Link
All the objects that have been inside your room for more than one hour are at room temperature. That is because heat flows from hotter to colder objects, so if you put a cold object inside the room, heat will flow to it until it reaches room temperature.
If we touch a piece of metal that is inside the room it feels cold. But when we touch the other objects of the room they don't feel as cold. Why is that? Why do metals seem colder than the other objects in the room although they have the same temperature?
Please, explain your reasoning. You can post your attempted answers in the comment box below. Please, do not use Facebook or Twitter to give your answers.
Our corporal temperature is higher than the temperature of the room. Metals are excellent conductors of heat, so the "Take" our temperature, leaving us a cold feeling
ReplyDeleteGood! A thermometer measures the temperature of the object, that is, the average kinetic energy of its atoms/molecules. But our hands are not thermometers. What we measure with our hand when we feel cold or warm is not the temperature but how fast heat is transferred between our hand and the object, because our hand is hotter than the object. The point is that metals are good heat conductors because they have electrons that can move almost freely through the whole piece of metal. Therefore, although the temperature of the metals that are inside our room is the same as the temperature of the other objects, they take heat from us at a higher rate and that is why they seem colder.
DeleteThis is a very useful cognitive conflict in order to teach students the structure of metallic crystal lattices in freshman (9th grade).