Originally Posted by
timster
You're doing it wrong. You have to use time not distance.
20 mph, 20 miles = 1 hour
average speed = 20 mph
25 mph, 10 miles = 24 minutes
15 mph, 10 miles = 40 minutes
average speed = 18.75 mph
Yeah, when I typed out my post I was thinking time, but typed distance.
Originally Posted by umd
But I am saying that *intuitively* you can't think has half the distance. Average speed is total distance / total time. You spend a lot less time going 25mph for half the distance than 15mph for the other half the distance and therefore the average has to be less than the no wind average. That's not taking into account that a 10mph wind doesn't affect each direction equally either...
When I said "On a very basic level, one would intuitively think that the tailwind would make up for the headwind, but this is not true", that basically means "considering it for 2 second during the ride."
I understand what you are saying, but IMO it isn't apparent when thought about briefly during a ride, given no prior thoughts / research on the subject.