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At 22:05 7/14/97 -0700, Leigh Palmer wrote:
[Ludwik]
[Leigh]Why is it misleading to say that "energy is the ability to do work"?
It's wrong. It doesn't mean anything. Now I retire from the fray.Leigh will not be satisfied it seems by anything less than this:
Leigh
"Energy: the property of a system that is a measure of its capacity for
doing work"
You might be excused for mistaking Ludwik's construction for the dictionary
definition that I take to be Leigh's view.
2)
I wrote that c is a constant, that no mass is lost, and that T is a state
variable. Thus the product m*c*dT is path independent. Leigh called this
quantity heat. But thermodynamics textbooks say that heat is not a state
function; it is a path-dependent quantity. That is why I think that the
phrase "a change in thermal energy" is more appropriate for c*m*dT. I am
still not convinced that this triple product, called dH (ethalpy) by
chemists, should be called heat. Enthalpy is a state function. Are we to
tell students, who studied chemistry before physics, that "ethalpy is heat"?
Enthalpy and energy are identical in our specific (vacuum) situation. Nobody
responded to that line of reasonning. Is it correct or not?
3)
Another line of reasoning was that "heat is that part of internal
energy which is transfered through a system boundary due to a difference
of temperatures". Leigh says "that definition makes the first law of
thermodynamics redundant. There should be no mention of internal energy
in the definition of heat." Please explain the redundancy pronouncement.
4)
.... How can you say, that "there is no heat involved in the
problem you stated"? How can I describe the so-called "work-heat equivalency"
experiment of Joule without saying that heat is involved?
6) Leigh:
....
The difference between saying "equal to the change" and "the change is
equal" is beyond my grasp; please elaborate, if you think it is an
important part of your argument.
....