Types of Energy in Thermodynamics-You need to know

In thermodynamics, energy is a key concept, and it can take on various forms depending on how it is stored, transferred, or transformed in a system.

Here are the primary types of energy relevant to thermodynamics:

Stored Energy:

Internal Energy.
Kinetic Energy.
Potential Energy.
Nuclear Energy.
Chemical Energy.
Mechanical Energy.

Transit Energy:

Work.
Heat.
Electrical energy.
Radiant Energy.

Energy and Types of Energy:

Energy:

Energy is the ability to do work or cause change. It exists in various forms, such as heat, light, motion, and stored energy, and can be transferred or transformed from one form to another.

In thermodynamics, energy can be classified into stored energy (contained within a system) and transit energy (energy in motion or transfer between a system and its surroundings). Here’s how the different types of energy fall into these categories:

Stored Energy (Intrinsic to the System)

Stored energy is the energy contained within the boundaries of a system. These forms of energy contribute to the system’s state.

Internal Energy (U)

Includes kinetic energy of particles (microscopic motion) and potential energy of intermolecular forces.
Examples: Molecular vibrations, chemical bonds, thermal motion.

Kinetic Energy (KE)

Energy due to the macroscopic motion of the system as a whole.
Formula: KE=12mv2KE = \frac{1}{2} mv^2KE=21mv2.

Potential Energy (PE)

Energy stored due to position in a force field (e.g., gravity, elasticity).
Examples: Water in a dam (gravitational PE), compressed spring (elastic PE).

Chemical Energy

Energy stored in chemical bonds.
Example: Energy in fuels, batteries, and food molecules.

Nuclear Energy

Energy stored in atomic nuclei due to nuclear forces.
Examples: Energy released during fission or fusion.

Mechanical Energy

A combination of macroscopic kinetic and potential energy in moving or deformable systems.
Examples: Rotating flywheels, moving fluids.

Transit Energy (Energy in Transfer)

Transit energy refers to energy that crosses the boundary of a system, typically in the form of heat or work. Transit energy is not stored and exists only during energy transfer.

Heat (Q)

Energy transfer due to a temperature difference between the system and surroundings.
Example: Heat flowing into a system when it is heated.

Work (W)

Energy transfer due to mechanical action (e.g., force over a distance, expansion, or compression).
Example: Work done by a gas expanding against a piston.

Radiant Energy

Energy transferred via electromagnetic waves.
Example: Solar energy (light and heat) reaching Earth.

Electrical Energy

Energy transfer via the movement of charges across a boundary (e.g., electrical currents).
Example: Energy flowing through power lines.