Examples of solving typical problems in the third section of the discipline "Theory of physical fields", which deals with the phenomena of heat conduction, diffusion and viscosity, as well as hydrodynamics and propagation of sound waves. Examples of solutions are preceded by brief theoretical information on each topic of this section. This teaching aid is intended for practical classes and organization of practical work of students studying in the direction of training "Instrumentation" . The manual can be used for classroom classes, for independent work of students studying in technical areas of training and specialties, in preparation for colloquiums, control works, offset, exam and centralized testing.