Technical term used in physics and engineering; often interchangeable with 速度 (そくど) but carries a more formal or scientific tone.
In this experiment, it is necessary to accurately measure the velocity of the object.
In physics, speed and velocity are strictly different concepts.
Compound of 速 (speed) + 力 (power) + 度 (degree). The exact historical derivation is uncertain; it appears to be a technical coinage for 'velocity'.