# Fifty Plus (50+) - Just for Fun - Calculate Average Speed

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DnvrFox
07-07-11, 08:51 PM
Just for FUN, please. Most of you have done this before, others may find it new and perhaps surprising. Anyway, it's time to revisit calculating average speed.

OK - if one goes 10 miles at 20 miles per hour and 10 miles at 10 miles per hour, what is the average speed?

Again, just for FUN :)

Dan The Man
07-07-11, 08:56 PM
The BF average is 22 mph because they don't count the stops and it was windy.

DnvrFox
07-07-11, 08:57 PM
The BF average is 22 mph because they don't count the stops and it was windy.

:) :)

B. Carfree
07-07-11, 09:23 PM
The BF average is 22 mph because they don't count the stops and it was windy.
...and it was ridden on an old steel bike, and the brakes were rubbing, and the tires weren't properly inflated, and it was too hot, too humid, too cold and too dry all at once (but only in the road forum).

Allegheny Jet
07-07-11, 09:30 PM
Is this a SAT test? Do trains still leave Denver @ .....

kenji666
07-07-11, 09:33 PM
Is there a headwind or any hills?

kenji666
07-07-11, 09:37 PM
If you do the math, you will find that if you climb a 5 mile hill slowly, and descend the other side (5 miles) very fast, your average speed is not your speed ascending plus your speed descending, divided by 2.

DnvrFox
07-07-11, 09:41 PM
If you do the math, you will find that if you climb a 5 mile hill slowly, and descend the other side (5 miles) very fast, your average speed is not your speed ascending plus your speed descending, divided by 2.

You're supposed to do MATH?? :eek:

kenji666
07-07-11, 09:46 PM
Or you can just count on your fingers and toes. ;)

DnvrFox
07-07-11, 09:53 PM
Or you can just count on your fingers and toes. ;)

That would get me to 22! That's a great average speed.

stonefree
07-07-11, 10:00 PM
Oh, I thought you meant what was our individual average speed. 22 is about my top speed down a wimpy underpass.

DnvrFox
07-08-11, 06:45 AM
Is this a SAT test? Do trains still leave Denver @ .....

Looks like most folks are going to make it into college, but only into colleges west of Denver.

Beverly
07-08-11, 06:48 AM
Or you can just count on your fingers and toes. ;)

Or I would just look at my Garmin and let it do the math for me;);)

Math was never my favorite subject........

Retro Grouch
07-08-11, 07:50 AM
I find that I go much faster and farther when I ride a bike that doesn't have a computer and estimate speed and distance.

stonefree
07-08-11, 08:50 AM
Two degrees is enough for me. Math is boring. Tunes rule. There's nothing west of Denver but fruits and nuts.

07-08-11, 09:15 AM
Try figuring out a golf handicap index some time.

Looigi
07-08-11, 09:21 AM
hint: (a+b)/(c+d) not equal to (a/c) + (b/d)

EsoxLucius
07-08-11, 09:22 AM
20/1.5

duceditor
07-08-11, 10:11 AM
20/1.5

:d

DnvrFox
07-08-11, 10:56 AM
20/1.5

There's always someone in the crowd who can't keep a secret :p

BluesDawg
07-08-11, 11:27 AM
There's always someone in the crowd who can't keep a secret :p

Probably that same one in every class in school who would raise his hand after every question saying "me, me, call on me..." ;)

CraigB
07-08-11, 11:43 AM
I find that I go much faster and farther when I ride a bike that doesn't have a computer and estimate speed and distance.

Agreed. Computers have a terrible effect on performance. Must be all that magnetic drag.

alicestrong
07-08-11, 11:49 AM
My average speed on the street is pretty slow, much faster on the San Gabriel River Trail, but I'm not sure many have the luxury of an almost flat, nearly empty smooth trail with (almost) no stops on which to measure their speed...

gcottay
07-08-11, 01:29 PM
You probably want the 4th grade arithmetic answer but I like to wander a bit. Okay, maybe more than a bit. Going ten miles can easily involve an extra ten miles of "Wonder what might be down that road/street/trail" and given that I never ride on a plane surface we'd have to get into various schemes for describing the topology of non-linear surfaces.

07-08-11, 07:27 PM
Just for FUN, please. Most of you have done this before, others may find it new and perhaps surprising. Anyway, it's time to revisit calculating average speed.

OK - if one goes 10 miles at 20 miles per hour and 10 miles at 10 miles per hour, what is the average speed?

Again, just for FUN :)

Vavg is equal to total distance divided by total time, assuming all time was spent riding as stated. Total distance is 10 +10 = 20. Total time duration is 10/20 +10/10, or 3/2 hours. Dividing 3/2 into 10, we get a long division problem of 40/3. The answer to that is 13.3 mph, rounded to one decimal place.

DnvrFox
07-08-11, 07:30 PM
Vavg is equal to total distance divided by total time, assuming all time was spent riding as stated. Total distance is 10 +10 = 20. Total time duration is 10/20 +10/10, or 3/2 hours. Dividing 3/2 into 10, we get a long division problem of 40/3. The answer to that is 13.3 mph, rounded to one decimal place.

And another who can't keep a secret :p :)

07-08-11, 07:31 PM
Good education is based on openness.

DnvrFox
07-08-11, 07:32 PM
Good education is based on openness.

woodway
07-08-11, 09:57 PM
Can you repeat the question?

HiYoSilver
07-12-11, 04:41 PM
If you poll 100 people on their average speed for that ride, 90% will say 20 MPH and .009% will say 13.3 mph :-)

Garilia
07-13-11, 10:00 PM
Rene Descartes walks into a bar, the bartender asks if he wants a drink. Descartes replies, "I think not." And he disappeared.

Just in case the OP was being philosophical and not mathematical.