What are the units of measurement (speed, distance, etc) in Unreal 4?

I’ve seen that 1uu = 1cm, but what are the units for speed?
For example, when a Projectile is spawned, an initial speed is specified, what does this float mean? meters per second, centimeters per second?

What about gravity of a Projectile? 1 means regular gravity (~= 10 m/s2)?

Thanks in advance.

Well if they just adding speed scaled to delta time the result will be cm/s

Thank you! I have been trying to figure this out.