Is there a difference between "pace" and "speed"? I have a feeling that with "speed" we usually specify the actual value, while with "pace" we talk more relatively. Am I right?
Yes, you are right.
Instead of speed you could use the word velocity. Either should include velocity units (distance units / time units) whenever mentioned.
Pace gives a relation to others performing the same task.
- Set the pace.
- He's not keeping pace.
- I can't work at the same pace.
- We have a pace setter for our 5k run.
- The pace car is on the track.
In some contexts, "pace" can mean the rhythm or tempo, so the speed of a person walking with short strides and a quick pace might equal someone walking with long strides and a slower pace.
In the context of running, "pace" can mean the inverse of speed. I.e., whereas speed is measured in units of distance per unit of time (e.g. miles per hour), pace is measured in units of time per unit of distance (e.g. minutes per mile).
Pace is the inverse of speed
Someone who travels at 60 km in 60 minutes has a SPEED of 60km per hour
However, if we reverse this, they have a PACE of 60 minutes per 60 km or rather .. their PACE is 1 minute per km.