30 m/s northwest is an example of velocity. Velocity is defined as Distance divided by Time.
Let me write an example.
Timmy was driving northeast, having a distance of 240m in 8s. What was his velocity?
To solve for his velocity, we'd have to divide our distance, 240m by our time, 8s.
240 / 8 = 30.
Timmy's velocity is 30 m/s NorthEast.
I hope this helps!