This is the 3577th most frequent Russian word.
скоростью
"Скоростью" means "speed" or "velocity" (instrumental case in Russian).
In this sentence, 'скорость' refers to the rate at which the car moves, specifically its velocity or speed.
Автомобиль развивает максимальную скорость 120 км/ч.
The car reaches a maximum speed of 120 km/h.
Here, 'скорость' is used to denote the swiftness or quickness of work being performed.
Чтобы уложиться в график, нужно работать на большой скорости.
To stay on schedule, one needs to work at high speed.
'Скорость' in this context describes the rapidity or velocity of the rocket's motion during launch.