speed= distance / time

ednino
Posts: 684
I've just put some 26x1.2 conti grand prix tyres on my MTB to use it on road for commuting during the week.
Its taken me 28.30 minutes to get 7.8 miles to work across very hilly wales. How do i work out my average speed? I know the formula, but its the units that i can't figgure out lol
thanks
Its taken me 28.30 minutes to get 7.8 miles to work across very hilly wales. How do i work out my average speed? I know the formula, but its the units that i can't figgure out lol
thanks

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Comments
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28.30 minutes = 28.30/60 hours = 0.4717 hrs
your average speed = 7.8miles / 0.4717 hrs = 16.54 mph
tenbar0 -
28 minutes 30 seconds = 28.5 minutes
Convert that into hours:
28.5/60 = 0.475 hours
Then calculate speed:
7.8/0.475 = 16.4 mph0 -
Well I work it out like this:
Mileage/(time/60) - so 7.8/(28.3/60)=16.54 mph average
Hope that helps0 -
Who's right? Was it 28 minutes 30 seconds or 28 minutes 18 seconds?
The excitement is killing me.0 -
Just do 7.8 / 28.30 to get your speed in miles / minute: but in an hour you go 60X further than a minute so
7.8 / 28.30 X 60 = 16.4mph
On second thoughts sod this, just get a bike computer0 -
or if you're feeling lazy: http://www.machinehead-software.co.uk/b ... _calc.html0
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It all depends if it was 30 seconds or 0.3 minutes. It's just like Eggheads this.0
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28.30 is 26 minutes 30 seconds which is 26 and a half minutes, not 26 and 3/10s
16.4 mph0 -
Lonzy wrote:28.30 is 26 minutes 30 seconds which is 26 and a half minutes, not 26 and 3/10s
16.4 mph
I think you'll find that 28.30 is actually 28 minutes....0 -
This is the most interesting cake stop has been for ages.
12 seconds......or not...ooohhh...the tension...0 -
Did anyone notice my deliberate, accidentally on purpose istake then ?
Go on, flame me...0 -
Or if you're feeling REALLY lazy, simply type '7.8 miles in 23.5 minutes' into WolframAlpha search engine. It does all the work for you
http://www.wolframalpha.com/Shazam !!0 -
DomPro wrote:Or if you're feeling REALLY lazy, simply type '7.8 miles in 23.5 minutes' into WolframAlpha search engine. It does all the work for you
http://www.wolframalpha.com/
It'll give you an answer, not the correct one as you did it in 28.5 minutes, but it will give you an answer0 -
LOL
Come on ednino was it 28.3 minutes or 28 minutes 30 seconds ??
The difference between 16.54 and 16.4 mph is crucial0 -
Keep it simple. My DB stores ride times as seconds, derived from the input form's three input fields, so (HH * 3600) + (MM * 60) + SS. To get the avg speed back it executes a query that returns (distance / seconds) * 3600 to get to hours.
My normal commute:
20.78m in e.g. 1h 3m 27s = 20.78m in 3807 seconds. (20.78 / 3807) * 3600 = 19.65mph.
Yours equates to
7.8 miles in (0 * 3600) + (28 * 60) + 30 = (7.8 / 1710) * 3600 = 16.42105 mph
Easy. And bang on - no rounding errors with parts of hours or minutes.0 -
...but if he..weighs the same .......as a duck....and a duck floats........
...a witch !
...burn him....!0 -
ChrisInBicester wrote:Keep it simple. My DB stores ride times as seconds, derived from the input form's three input fields, so (HH * 3600) + (MM * 60) + SS. To get the avg speed back it executes a query that returns (distance / seconds) * 3600 to get to hours.
My normal commute:
20.78m in e.g. 1h 3m 27s = 20.78m in 3807 seconds. (20.78 / 3807) * 3600 = 19.65mph.
Yours equates to
7.8 miles in (0 * 3600) + (28 * 60) + 30 = (7.8 / 1710) * 3600 = 16.42105 mph
Easy. And bang on - no rounding errors with parts of hours or minutes.
I believe there are rounding errors in there. My understanding is that your answer cannot have more decimal places then the value with the fewest decimal places. Though I could be wrong! :P0 -
Well spotted. I went overboard with the decimal places just to make the point. In the db it rounds down to two places but there was no need to add complexity to the suggested answer on here. Good spot though. Take the rest of the morning off.0
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ChrisInBicester wrote:Keep it simple. My DB stores ride times as seconds, derived from the input form's three input fields, so (HH * 3600) + (MM * 60) + SS. To get the avg speed back it executes a query that returns (distance / seconds) * 3600 to get to hours.
My normal commute:
20.78m in e.g. 1h 3m 27s = 20.78m in 3807 seconds. (20.78 / 3807) * 3600 = 19.65mph.
Yours equates to
7.8 miles in (0 * 3600) + (28 * 60) + 30 = (7.8 / 1710) * 3600 = 16.42105 mph
Easy. And bang on - no rounding errors with parts of hours or minutes.
But I think you're assuming the OP posted 30 seconds. In which case you're correct but it could be 0.3 of a minute (18 seconds) in which case it would be 16.54mph
Come on OP0 -
44 451.7314 furlongs per fortnight0
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Escargot wrote:But I think you're assuming the OP posted 30 seconds. In which case you're correct but it could be 0.3 of a minute (18 seconds) in which case it would be 16.54mph
Come on OP
No you're right there to highlight the ambiguity. OP stated 7.8 miles in 28.30 minutes, not 28:30. 28.3 minutes is, as stated, 28:18.
We can only work with the data as supplied - it's not for us to second guess the format, or to assume that 28 point 3 really meant 28 point 5. Stick at 28:18 / 16.54
Who says punctuation doesn't matter eh?0 -
ChrisInBicester wrote:Escargot wrote:But I think you're assuming the OP posted 30 seconds. In which case you're correct but it could be 0.3 of a minute (18 seconds) in which case it would be 16.54mph
Come on OP
No you're right there to highlight the ambiguity. OP stated 7.8 miles in 28.30 minutes, not 28:30. 28.3 minutes is, as stated, 28:18.
We can only work with the data as supplied - it's not for us to second guess the format, or to assume that 28 point 3 really meant 28 point 5. Stick at 28:18 / 16.54
Who says punctuation doesn't matter eh?
LOL
Can't belive this thread is onto 2 pages of discussion over 0.12mph
I apologise for being so pedantic but work is really dragging today0 -
dont forget that it needs to be converted to kph so you can be like the continental chaps, plus 26.6 kph sounds faster than 16.5 mph!0
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thanks for all the help
Its was 28 minutes 30 seconds
So 16.4mph
Im happy with that, i'll do a 10 mile blast on the flat later to see what im doing without all the hills to slow me down 8)0 -
17.9mph on the flat
not as much difference as i expected0 -
That's more than you think... think Contador won a month long race by a few minutes!0
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That is quite a difference. if you'd set off against yourself you'd be a mile & a half further up the road after an hour. Or in reverse terms, you'd do that 7.8 miles about 1m 15s faster.
You don't see huge jumps in performance, just steady incremental diffs that accumulate. Soon a 16.4 mph avg will seem like a bimble to the shops.0