The phrase "a certain speed of" is correct and usable in written English.
It can be used when discussing a specific but unspecified speed in various contexts, such as physics, engineering, or everyday situations.
Example: "The car was designed to operate efficiently at a certain speed of 60 miles per hour."
Alternatives: "a specific speed of" or "an unspecified speed of".
However, rotation's impact is negligible above a certain speed of rotation after which the sudden increase of cutting's accumulation caused by eccentricity is not observable.
That very distinct atmosphere he creates, with its volatile combination of religious stricture and eruptive sexual urges, drab reality and fantastical cabalistic mystery, thrives on a certain speed of entry and exit, for which the short story is the ideal form.
Thereafter, the cutting tool moves along Z [001] direction at a certain speed of 50 m/s to start the nano-cutting process.
Many online teaching companies require a certain speed of broadband, to ensure that the quality of education given by the teacher is not diminished by blocky visuals, dropped signals or other aspects of a spotty Internet connection.
It forces a certain speed on the process of evaluating their technologies.
— Running economy: The ability to maintain a certain speed for a given amount of oxygen used.
The team's experimental results suggest that the surface electrons plunge into the crystal only when traveling at a certain speed and direction of travel called the Weyl momentum, said Yazdani.
But if a ball moves faster than a certain speed, the size of the wake suddenly decreases and the drag plummets.
When the vehicle is moving to the border of one BS in a certain speed, the signal quality of the SBS begins to degrade.
In the abrasive flow polishing process, the suspended particles in the medium will flow along the media, at a certain speed with the impact of micro cutting workpiece surface (Fig. 1).
The AA favours the system used in Germany and Austria, where collisions below a certain speed (assessed by expert analysis of vehicle damage) are deemed to be too low to result in whiplash injury – around 70% of road accident personal injury claims are for whiplash in the UK, compared with 47% in Germany.
