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calculating speed(12 posts)

calculating speediatola-rocnrola
Oct 9, 2003 1:12 PM
can someone give the math equation for calculating speed. for instance if i did a 23.4 km tt in 47min 23 secs? what was the average speed?
re: calculating speedXeo
Oct 9, 2003 2:25 PM
To calculate km/hour given length and time, you use basic dimensional analysis.

Here is how you set up the problem

Number (km) / number (min) * 60 min / 1 hour = speed/hour

Basically you start off in km per minute and you want km/hour, so you use a conversion factor.

This is what your speed was.

23.4 km / 47 min * 60 min / 1 hour = 29.87 km/hr

If you want miles per hour just divide 29.87/1.6 = 18.66

I rounded the minutes but it is basically accurate.

~Marc
thanks much appreciated...nmiatola-rocnrola
Oct 9, 2003 2:31 PM
(hint - any value divided by 1 is equal to itself). nm.Steve_0
Oct 10, 2003 7:37 AM
re: calculating speedcollinsc
Oct 9, 2003 2:26 PM
23 seconds
23/60 = .383 minutes
+ 47 minutes = 47.383 minutes / 60 = .7897 hrs

23.4 km / .7897hrs = 29.63 km/hr = 18.41 mph
More info than you'll ever need...coonass
Oct 9, 2003 3:45 PM
http://www.analyticcycling.com/
http://www.tenlinks.com/cycling/science.htm
online calculator hereTime Trial dot org
Oct 9, 2003 4:06 PM
www.timetrial.org/speed.htm
"per" means "divided by" - kilometers "divided by" hour(s) nmBowWow
Oct 9, 2003 9:59 PM
I think you need more than an equationniteschaos
Oct 10, 2003 5:03 AM
Perhaps a trip back to elementary math? Yeah, you'd get alot out of it. Just don't forget your units. mph = miles per hour = miles/hr = Distance/time. I bet your checkbook looks like a mess.
That was uncalled for (nm)OffTheBack
Oct 10, 2003 6:04 AM
aaaarrrrrrrRRRRRRRRRHHHHHHHHHHHHHHHHHSteve_0
Oct 10, 2003 5:42 AM
did no-one pay attention in 3rd grade math?

Does no-one understand the significance of the term Miles per hour?

No offence to rocnrola specifically, I just cant fathom how often this question is asked.
speed calculation4bykn
Oct 10, 2003 1:30 PM
This is the formula I use in my spreadsheet:

Miles/(hours+(minutes/60)+(seconds/3600))

or in plain english:
Miles divided by the sum of these three:
1) Hours
2) Minutes divided by 60
3) Seconds divided by 3600