maths question?

[hovis]

if i was to do miles (5km) in 27 mins


whats the formula for working out.....

mph
and
kmph



:confused:

[Alpinestarhero]

speed = distance / time (miles / hours or kilometers / hours)

given that 27 mins is approx. 0.5 hours, 5km / 0.5 hrs = 10 k/h (kph)

conversion factor

1 mile = approx. 1.6 kph

5 / 1.6 = ? miles

[the_lone_wolf]

speed = distance divided by time

1mile = 1.6km

1hour = 60 minutes

therefore your speed in km per minute is 5 divided by 27 = 0.185...

multiply by 60 to get km per hour = 11.1...

divide by 1.6 to get miles per hour = 6.94...

so ~7mph

[Mr Speirs]

Kms Covered/Time = km per min

m per min x 60 = m per hour

you were doing 11.11kph.

To convert it to MPH you

kph/8 then multiply by 5. = 6.875mph

[SoulKiss]

if i was to do miles (5km) in 27 mins


whats the formula for working out.....

mph
and
kmph



:confused:

Well you need to break it down into miles per minute - so divide 5 by 27 = 0.185.

To get kmph from that just multiply by 60 = 11.1 kmph

Then just apply the conversion from km to mls where 1kmph = 0.621mph

Leaves you with 6.9mph

[Ceri JC]

My calculations:

For Km. (60/27) x 5 =11.111... (kmph)

For Miles. 5km=3.1 miles, so (60/27) x 3.1 = 6.8 (Mph)

[kwak zzr]

where was u going at 7mph hovis?

[SoulKiss]

speed = distance divided by time

1mile = 1.6km

1hour = 60 minutes

therefore your speed in km per minute is 5 divided by 27 = 0.185...

Multiply by 60 to get km per hour = 11.1...

Divide by 1.6 to get miles per hour = 6.94...

So ~7mph

wrong

c-

[hovis]

where was u going at 7mph hovis?

on foot;)

[Alpinestarhero]

but his working out means he'll pass...ah, good ol' GCSE's.


although, i'd ratyher have someone builidng my aircraft who got the right answer but negected to show his/her working out...

[hovis]

Kms Covered/Time = km per min

m per min x 60 = m per hour

you were doing 11.11kph.

To convert it to MPH you

kph/8 then multiply by 5. = 6.875mph

wrong

c-

Well you need to break it down into miles per minute - so divide 5 by 27 = 0.185.

To get kmph from that just multiply by 60 = 11.1 kmph

Then just apply the conversion from km to mls where 1kmph = 0.621mph

Leaves you with 6.9mph

:confused:

but you both got the same answer

[the_lone_wolf]

speed = distance divided by time

1mile = 1.6km

1hour = 60 minutes

therefore your speed in km per minute is 5 divided by 27 = 0.185...

multiply by 60 to get km per hour = 11.1...

divide by 1.6 to get miles per hour = 6.94...

so ~7mphwrong

c-

explain...:rolleyes:

[SoulKiss]

:confused:

but you both got the same answer

Your Quote-Fu is weak Bread-boi

I was referring to TLW's 7mph, not "oops I did it again's" 8.875mph

[the_lone_wolf]

I was referring to TLW's 7mph

where's the error then?

[SoulKiss]

explain...:rolleyes:

Multiply by 0.621 rather than divide by 1.6......

[hovis]

im :confused:.com

[the_lone_wolf]

Multiply by 0.621 rather than divide by 1.6......

do me a favour...

go find your ELC "My first calculator"

type in 1 / 1.6

did you get 0.625?;)

unless you're going to give him completely unecessaarily accurate answers the assumption on 1mile = 1.6km is perfectly valid for the purpose

[21QUEST]

Multiply by 0.621 rather than divide by 1.6......
Same thing ;)

edit:Oops the terrier...errr TLW got in first :mrgreen:


Ben

[SoulKiss]

do me a favour...

go find your ELC "My first calculator"

type in 1 / 1.6

did you get 0.625?;)

unless you're going to give him completely unecessaarily accurate answers the assumption on 1mile = 1.6km is perfectly valid for the purpose

1 decimal place is not ott for accuracy :P

(also the fact that I speed-read your post and only saw that you had a 7 instead of a 6, so in my haste had the difference as greater than .1 :twisted:)

I'll upgrade your mark to a B+ then :)

[the_lone_wolf]

1 decimal place is not ott for accuracy :P
it's two dp not one

comparing 0.621 to 0.625 constitutes an error of 0.64% - if you can tell me how fast you're walking to that accuracy then perhaps the extra dp would be justified, for any normal person zero dp or even one is plenty accurate

A+ for commitment

D for fact checking...

:mrgreen:

[Ed]

What he really needs is the answer in minutes per mile, ie was he running at 8 mins/mile, 8.5 mins/mile, etc

Back to the drawing board:D

[hovis]

What he really needs is the answer in minutes per mile, ie was he running at 8 mins/mile, 8.5 mins/mile, etc

Back to the drawing board:D

thats what you want me to know.......

which i can do (i think)

just divide the distance by the time

ie

5km= 3 miles

3 miles divded by 27 mins= 9 minuite miles

[21QUEST]

thats what you want me to know.......

which i can do (i think)

just divide the distance by the time

ie

5km= 3 miles

3 miles divded by 27 mins= 9 minuite miles
Err It's actually 8.64 :rolleyes: :smt040



Ben

[Stu]

thats what you want me to know.......

which i can do (i think)

just divide the distance by the time

ie

5km= 3 miles

3 miles divded by 27 mins= 9 minuite miles
Yes, 8.65 minute miles

edit too slow, me, not your walking

[hovis]

Err It's actually 8.64 :rolleyes: :smt040



Ben

Yes, 8.65 minute miles




how come?

i take it you are working it out being 3.1 miles


and then how do i convert 8.65 into mins and secs

[21QUEST]

Yes, 8.65 minute miles

edit too slow, me, not your walking
Wrong :o hehe

Rounding up to two decimal places should be 3.13 and not 3.12 :p


Ben

[21QUEST]

how come?

i take it you are working it out being 3.1 miles


and then how do i convert 8.65 into mins and secs
I used 3.125 for super accuracy lol



Ben

[hovis]

I used 3.125 for super accuracy lol



Ben

i like accuracy............ but im going off google maps,

[Mr Speirs]

Your Quote-Fu is weak Bread-boi

I was referring to TLW's 7mph, not "oops I did it again's" 8.875mph

It was 6.875mph for oops it did it again :)

[ophic]

you've forgotten to take into account the movement of the earth. The real answer is 1 million .38753422879 miles per hour :smt019

[Mr Speirs]

Actually if the earth rotated at a million miles an hour our days would be 90 seconds :)

[Ed]

thats what you want me to know.......

which i can do (i think)

just divide the distance by the time

ie

5km= 3 miles

3 miles divded by 27 mins= 9 minuite miles

I'd divide the time by the distance...

[Baph]

Geeks the lot of ya! :rolleyes:

[ophic]

Actually if the earth rotated at a million miles an hour our days would be 90 seconds :)
ah but its going round the sun, which in turn is also orbiting something centrally located in the milky way, which is in turn also zooming around due to universal expansion blah blah blah. My figure was totally accurate until proven otherwise :D

[Mr Speirs]

Damn and blast you and your clever wording.

[BoltonSte]

I use http://joshmadison.com/article/convert-for-windows/ this little number is great for converting between different units for a whole host of measurements.

Ste

[anna]

Geeks the lot of ya! :rolleyes:

Pot, Kettle and Black

[ophic]

I use http://joshmadison.com/article/convert-for-windows/ this little number is great for converting between different units for a whole host of measurements.

Ste

I just bang it into google.

http://www.google.co.uk/intl/en/help/features.html#calculator

[cmsd2]

I just bang it into google.

http://www.google.co.uk/intl/en/help/features.html#calculator

indeed:

"5km per 27 minutes in miles per hour"
http://www.google.co.uk/search?&q=5km+per+27+minutes+in+miles+per+hour

easy peasy :)
also works for other conversions:

75 horsepower in (miles * furlongs * tons per fortnight per second per second)

some are more useful than others, but you need to get the units right whatever you do (use F=ma, P=FV=E/t etc etc to guide you)

[ophic]

oooh i didn't realise it was that clever :D

[Alpinestarhero]

:confused:

but you both got the same answer

7mph was correct, given the maximum significant figures you can quote to (one, since the number of "5" was the data given with the least amount of sig. fig)

[Stu]

how come? - taking the genaerally accepted answer of 6.94mph. 60mins divide by 6.94 = 8.65 mins per mile*

i take it you are working it out being 3.1 miles - err no :confused:


and then how do i convert 8.65 into mins and secs - = 8 mins and 0.65 times 60 = 39 secs

*But A*Hero is right 60 divide by 7 = 9 min miles, seeing as you are starting with rough figures