Kiihdytyksissä

Kiihdytyksissä is a Finnish noun phrase that translates roughly as “in accelerations” or “during acceleration phases.” It is the inessive plural form of kiihdytys, which denotes speeding up or boosting rather than the instantaneous rate of change. The expression is used to refer to events, observations, or processes that occur within periods of increasing speed.

In scientific and technical contexts kiihdytys describes a phase during which speed or momentum increases, such as the burn of a rocket engine or the acceleration segment of a vehicle’s performance test. In everyday language the term can describe any period of rapid change or growth, though kiihdytys is more common in reference to mechanical or technical speeding up. The standard mathematical term for acceleration is kiihtyminen, so kiihdytys/kiihdytykset appears mainly in engineering, automotive, or colloquial usage.

Grammatically, kiihdytyksissä combines kiihdytys (acceleration) with the inessive plural suffix -issä, indicating “in” or “during” multiple accelerations or a particular acceleration phase. It is usually used with verbs that describe observations or actions taking place during that phase, for example: “Tutkimuksessa mitattiin lämpötilan muutos kiihdytyksissä” (In the study, temperature changes were measured during accelerations).

Related terms include kiihtyminen (acceleration in a general physics sense) and kiihdytys (the act or process of speeding up). The use of kiihdytyksissä is most common in engineering, automotive, or technical Finnish, and occasionally in metaphorical expressions to describe rapid change.