The word "velocity" is probably the most misused scientific sounding words out there. This is just a quick post explaining that velocity addresses the speed and direction of travel, whereas speed addresses only rate of travel.
If you say he has a velocity of 45 meters per second, and just that, you are leaving something out. You need to have the direction of travel when using the word velocity.
This is especially annoying when it is only used to make the speaker sound smarter than he really is. Maybe he is smart, but just missed that fact. I don't know. But if you do not know the direction they are going, please do not use tho word velocity, use the correct term: speed.