Otáky

Otáky, more correctly otáčky, is a Czech term used to denote the number of full turns a rotating object makes in a given period. The standard spelling with diacritics is otáčky; the non-diacritic form otáky is common in texts that omit diacritics. The singular form is otáčka. In English, the concept is usually expressed as revolutions per minute when describing engine or machine speed.

Etymology and meaning: Otáčka comes from the verb otáčet, meaning "to turn" or "to rotate," with a productive noun suffix. The word denotes a rate of rotation, i.e., how many times something completes a circle per unit of time.

Usage: The term is widely used in automotive, mechanical, and technical contexts. In cars, a tachometer displays engine speed in otáčky za minutu. In machining and manufacturing, otáčky describe the rotational speed of spindles, gears, mills, lathes, and other rotating components. In physics and engineering, rotational speed is discussed in terms of otáčky per unit time, sometimes without reference to machinery.

Measurement and notation: The standard unit is otáčky za minutu (often abbreviated ot./min. or rpm). In some technical contexts, revolutions per second (rps) may be used, particularly in scientific literature. Precise specifications of otáčky are important for performance, wear, efficiency, and dynamic behavior of rotating systems.

Related concepts include tachometer, rotational speed, angular velocity, and gear ratios. Otáčky provide a concise measure of how fast a rotating element operates and are central to design, operation, and maintenance across many fields.