PHY的一條問題~英文答

Question

can heat flow from a body with a smaller amount of internal energy to another body with a higher amount of internal energy?give an example if any?

Answer 1

Yes, heat can.

The flow of heat from one object to another only depends on the temperature DIFFERENCE between the two objects, and is irrespective of the internal energy they posses.

Note that the amount of internal energy an object possesses has nothing to do with its temeprature. It is incorrect to say that an object with large internal energy must have high temperature. Likewise, an object with small internal energy is not necessary at low temperature.

Example:
The internal energy of the water in a standard swimming pool is larger than that of a piece of iron (say, of mass 100g) at 300 deg.C. But when the piece of iron is thrown into the swimming pool, heat will flow from the iron to the water because of the temperature difference between the two.

Answer 2

I think that heat can flow from a body with a smaller amount of internal energy to another body with a higher amount of internal energy.

[copy from Physics in life: Heat p.27]
*Internal energy can be interpreted as the energy stored in a body. It depends on the MASS and the TEMPERATURE of the body.
*Heat is the energy transferred from one body to another as a result of a temperature difference between the bodies.

Here is what i think, sorry.. I'm poor in english. I can't show it by words
A -----------> B
Hotter object --Heat--> colder object
High KE -----------> Low KE
if this condition appear:
Low IE ------------> High IE
for two object A and B,
if A has a higher KE that B but lower IE than B, A's mass must be smaller than B very very much. so that...
Very Low Mass --------> Very High Mass

so that...
object A must be a thing that with Higher temperature but Lower mass.
object B must be a thing that with Low temperature but Higher mass...

example
A: Very little water vapour above 100 degree
B: Very large amount of Ice under 0 degree


I don't know if it is true to think like this.

2007-01-02 01:36:59 補充：
*Internal energy can be interpreted as the energy stored in a body. It depends on the MASS and the TEMPERATURE of the bodyThis is one of the easy way to explain IE, it is also trueThe other meaning is the sum of the KE of random motion and the PE of all its molecules.