Why can a system extract heat from an environment at constant temperature for free?

Question

Cheyanne Charles · Accepted Answer

Assume that the surroundings are infinitely large and at temperature       T    ∞  , and that the system and surroundings are in thermal contactIf the system is at   T  &amp;gt;      T    ∞   then there will be spontaneous heat transfer from the system to the surroundings until the system reaches       T    ∞  If the system is at   T  &amp;lt;      T    ∞   then there will be spontaneous heat transfer from the surroundings to the system until the system reaches       T    ∞  This heat energy comes &quot;for free&quot; in that it is given to/taken from the system all by itself. The experimenter doesn&#039;t need to give or accept any energy to help the system reach equilibrium.Note that it&#039;s not possible to heat the system above       T    ∞   (or cool it below       T    ∞  ) &quot;for free.&quot; The only change that is &quot;free&quot; is bringing the system to       T    ∞   and keeping it there.

Why can a system extract heat from an environment at constant temperature for free?

Answered question

Answer & Explanation

New Questions in Thermal Physics