Question

How do I find average velocity over a given time interval?

Answer 1

Average velocity = total distance / total time

Example:
I travel from Rotterdam to Amsterdam (100 km) with an average speed of 80 km/h and return with an average speed of 120 km/h.

Then my average verlocity is NOT 100 km/h, but:

Time for the trip out: `(100km)/(80km//h)=1.25h`

Time for the trip back: `(100km)/(120km//h)~~0.83h`

Total time: `1.25+0.83=2.08h` over `200 km`

Average velocity: `200/2.08=96.0km//h`

This may be counter-intuitive, but remember you spend more time in the slow mode than in the fast mode.