Chronology | Current Month | Current Thread | Current Date |
[Year List] [Month List (current year)] | [Date Index] [Thread Index] | [Thread Prev] [Thread Next] | [Date Prev] [Date Next] |
Here's an analogous gravitational
case:
I drop a ball from rest from some height. (System=ball.) It gains KE.
Why? Well, because the earth pulled it downward while the ball was
moving downward and hence did positive work on it.
But work is an energy transfer from one object to another, right?
Therefore since the ball (adiabatically) gained energy, the earth
must have lost energy....
I think this is what John may mean by dubious energy accounting. The
problem is we forgot to include the gravitational field in our story;
it is the "third object" and it can gain/lose energy. Carl