Speed is the term that defines the rate of which something (car , flight , running man , .... ) is displaced per a second.
no of meters crossed per a second that is for linear speed , another type of speed is the rotational speed which measures the no of radian angles per second crossed by rotating part ... speed is a scalar measurement.
velocity defines the rate of displacement (meters or angles) beside direction in which displacement is taken (vectorial measurement --> magnitude and direction).
It is called a definition.
The definition of the speed of light in a vacuum is 300,000,000 meters/sec, or 186,000 miles/sec.
Initial speed is the original, beginning speed of an object.
they are fast
Quickness, speed
The speed that an object moves through the air.
Great speed is faster than normal.
"instantaneous speed"
By definition acceleration is the change in velocity (speed).
Something that is not restricted to running at one speed.
The definition of haste is: swiftness of motion; speed; celerity or unnecessarily quick action; thoughtless, rash, or undue speed
Acceleration is when speed increases. Deceleration is when speed decreases.