— fixed physical quantities that are quantitative and qualitative characteristics of the main components of a structural nature, reflecting their systemoutvorennya, relationship and interaction. Ph. c., included in the mathematical expressions or fundamental physical laws describing the fundamental particles and processes microworld called fundamentals (eg., Gravitational constant, Planck constant, velocity of light in vacuum). Ph. c. experimentally determined with maximum precision for quantitative study of physical phenomena and verification of physical theories.

— solid, oscillating gravity around a fixed horizontal axis that passes through its center of gravity. The period of small oscillations of Ph.p. equal $$ T=2 \pi \sqrt{\frac{I}{m g d}}=2 \pi \sqrt{\frac{l_{n p}}{g}} $$ where $I$ — moment of inertia Ph. p. relative to its axis, $m$ — mass Ph.p., $d$ — the distance from the axis of rotation of the center of gravity, $l_{n p}=\dfrac{I}{m d}$ — reduced length of the physical pendulum.

— any change, transformation or manifestation of the properties of matter in which its composition remains constant, ie the molecules of matter will not be affected (see, eg., Boiling, Melting, Scattering of light, Photoeffect, photoelectric effect).

— a set of ideas about the nature (matter, motion, space and time), based on the most general principles, hypotheses and theories of physics at a certain stage of its development. Thus, eg., the emergence of classical mechanics accompanied the creation of mechanical,electrodynamics — the electromagnetic and the theory of relativity and quantum mechanics — quantum-relativistic world view.

— property, general qualitatively many physical objects (physical systems and their states and processes occurring in them), but in numbers for each individual object. The concept of F.q. apply to the properties of physical objects or characteristics that are measurable (see. also Value of physical quantity, Size of units of physical quantities).

— physics section, which examines the properties and the possible interaction of “structure” of elementary particles. F. experimental means to. e. — the accelerator of charged particles and target for cosmic rays.

— the science of simple and yet the most common form of movement and interaction of material objects. Studies elementary particles, atomic nuclei, atoms, molecules, solids, liquids, gases, plasma and physical fields. According to research methods distinguish between experimental and theoretical F. fundamental physical theories: classical mechanics, electrodynamics, the theory of relativity, quantum mechanics and statistical physics and thermodynamics. F. laws form the basis of science and is the theoretical foundation of modern technology.

— selective acquisitions ferromagnetic Alternating electromagnetic field at frequencies that are determined by their electronic structure.

— substances that show ferromagnetism. Typical representatives F. — iron, cobalt, nickel and alloys, and a variety of rare earth metals (gadolinium, terbium, dysprosium, etc.). F. widely used in electrical engineering, electrical engineering, electronics and instrumentation.

— a set of properties and magnetic phenomena in magnetic crystalline solid (ferromagnetic), with spontaneous magnetization. F. due to the presence of positive exchange interaction of electrons, resulting in a stable parallel orientation of the magnetic moments of the spins, which creates spontaneous magnetization. The thermal motion of the atoms of the crystal orientation parallel breaks spins, because at some specified above (see. Curie point) F. goes to paramagnetism.