One-way processes: Some processes will happen only in a
certain way: heat flows from hot to cold, not the other way
around, and air spreads throughout a room, but never get
concentrated in only the left half of the room. Energy
conservation is satisfied even if a process goes the wrong way;
the fact that it does not mean that there must be another
property of the system that defines whether a process occurs.
This is entropy.
For an irreversible process in a closed system, entropy
always increases; in a way, entropy change defines the arrow of
If an amount of heat Q is added to a system at constant
temperature T, the entropy changes by Q/T.
The entropy statement of the second law of thermodynamics:
The entropy of a closed system never decreases. For an
irreversible process the change of entropy is positive; for a
reversible process it is zero.
Entropy and Second Law of Thermodynamics
Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.
The book offers a complete review of your AP course, strategies to give you the edge on test day, and plenty of practice with AP-style test questions. It includes full length practice exams modeled on the real test and all the terms and concepts you need to know.
This book includes a review of all the topics tested including vectors, kinematics, fluid mechanics, optics and nuclear physics. Additionally, the book includes two full length tests made complete with descriptive solutions, and quick study tables for Physics B formulas and equations.