seclawthermo

seclawthermo - Second law of thermodynamics & heat engines...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Second law of thermodynamics & heat engines Some processes one might imagine obey the first law of thermodynamics but still do not happen. For example, heat flows spontaneously from hot to cold but not from cold to hot even though this would conserve energy too. Other examples include ageing, dropping an egg, etc. . The second law of thermodynamics shows why some imaginable things do not happen even though they conserve energy. In short, the second law concerns ordered and disordered forms of energy. The mathematical statement of the second law comes in various forms. Sometimes it is stated in terms of entropy and other times in terms of heat engines. • ∆ S isolated > 0 (a statement of entropy non -conservation) It is impossible for a heat engine to have 100% efficiency. But what is entropy , S? The way this is defined in thermodynamics is very precise:
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
S dQ/T , where T must be in Kelvin. rev
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/29/2011 for the course PHY 2048 taught by Professor Chen during the Spring '08 term at UNF.

Page1 / 4

seclawthermo - Second law of thermodynamics & heat engines...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online