The distance travelled divided by time. Distance/time = speed
Velocity is defined as the speed in a given direction. It is a vector quantity that includes both the magnitude (speed) and direction of motion.
speed
Distance divided by Time
speed and wind
Velocity is defined as speed in a certain direction, or vector.
Why? Because that's the way speed and velocity are defined.
"Speed" is.
Instantaneous speed is the speed at a specific instant. It is calculated as the average speed (defined as distance / time), for very small times.
The speed of light in vacuum is defined to be exactly 299,792,458 metres per second.
Speed.
That is velocity.
That's how "Mach" is defined.