Thermodynamics

Thermodynamics (What)

Thermodynamics (thermo) is a subject that involves heat, work, energy, power, temperature, and related topics.

Thermo is based on four fundamental laws, often referred to as the Zeroth, First, Second, and Third Laws of Thermodynamics. In practice, many thermo problems are solved by applying the First or Second laws. That is, the Zeroth and Third laws are not commonly applied. Here are the laws in brief:

  1. Zeroth Law: If two systems are each in thermal equilibrium with a third system, they are in thermal equilibrium with each other. This law establishes the concept of temperature and provides a foundation for the construction of temperature scales.

  2. First Law (Law of Energy Conservation): Energy cannot be created or destroyed; it can only be converted from one form to another. Mathematically, it’s expressed in its fundamental form as ΔE = Q − W where ΔE is the change in internal energy of a system, Q is the heat added to this system, and W is the work done by this system.

  3. Second Law: Energy spontaneously tends to disperse or spread out if it’s not hindered from doing so. Alternatively, in processes where energy is converted, some of it will become more disordered and rejected as waste heat. This limits the useful work that one can get from engines and power plants.

  4. Third Law (Nernst Heat Theorem): As the temperature approaches absolute zero (0 Kelvin), the entropy of a perfect crystalline structure approaches zero. In other words, molecular motions decrease as the temperature approaches absolute zero, and entropy reaches its minimum value.

Rationale

Here are some reasons why learning thermodynamics is worthwhile.

Thermo is useful for dealing with many problems in the real world that involve energy, heat, work, power, and such.

Topics from thermodynamics are needed to understand heat engines, power plants, machines such as compressors and turbines, phase transitions, chemical reactions, and even the dynamics and fate of the universe in cosmology.

Thermo is a prerequisite subject for multiple other subjects.

Facts

Who Should Learn Thermo

People who are pursuing expertise in engineering and related scientific fields may benefit from learning thermo.

When to Learn Thermo

Learn thermo after you have learned chemistry and calculus.

Excelling at Thermo (How To)

  1. Learn the main ideas of thermo.

  2. Concurrently learn the common skills that are used by engineers, scientists, and the like; here are some of these skills: problem-solving, design, modeling, estimating, and computer programming.

  3. As you are learning thermo plus the empowering skills, apply these topics together in the real world over and over. That is, learn by using the method of learning called “Deliberate Practice.”