question for you all

[hugoagogo]

you have a piece of string that reaches all the way around the equator of the earth, 24,901.55 miles long

if you want this piece of string raised 12 inches from the ground all the way round, how much longer must it be?
(assume the equator is all sea and has no hills etc)

extra points for showing your working

[mybrainhurts]

How long is a piece of string...?

[hugoagogo]

yes indeed

[hugoagogo]

if you like

[mybrainhurts]

Like what..?

[T40ORA]

hugoagogo said:

you have a piece of string that reaches all the way around the equator of the earth, 24,901.55 miles long

if you want this piece of string raised 12 inches from the ground all the way round, how much longer must it be?
(assume the equator is all sea and has no hills etc)

extra points for showing your working

Innit 2 time pie times 12?

2 times pie times r gives diameter. If r is 12" greater, the 2 times pie times (r pls 12). So difference is 2 times pie times 12.

Mind you, 30 years since I passed my two maths A levels, so I'm very probably totally wrong!

[hugoagogo]

mybrainhurts said:

Like what..?

if you like to work it out like that

[andyquantum]

It'd be shorter.

3 foot shorter

[King Herald]

anonymous said:

[redacted]

Well, that's the hypothesis, but can you prove it?

This is PH: solid evidence matters.

[ewenm]

A more difficult question is how much longer if you grab the string and raise it 12 inches at just one point.

[enioldjoe]

What if someone wants to use it to hang their washing on? That's going to raise it a bit more than twelve inches.Hmm? We're talking serious maths then.

[hugoagogo]

T40ORA said:

hugoagogo said:

you have a piece of string that reaches all the way around the equator of the earth, 24,901.55 miles long

if you want this piece of string raised 12 inches from the ground all the way round, how much longer must it be?
(assume the equator is all sea and has no hills etc)

extra points for showing your working

Innit 2 time pie times 12?

2 times pie times r gives diameter. If r is 12" greater, the 2 times pie times (r pls 12). So difference is 2 times pie times 12.

Mind you, 30 years since I passed my two maths A levels, so I'm very probably totally wrong!

they've shortened the name to 'pi' in the last 30 years, but otherwise well done

didn't reel in as many 'long way round' worker-outers as i hoped

[Saskia7]

hugoagogo said:

you have a piece of string that reaches all the way around the equator of the earth, 24,901.55 miles long

if you want this piece of string raised 12 inches from the ground all the way round, how much longer must it be?
(assume the equator is all sea and has no hills etc)

extra points for showing your working

How is this a hard question? if the string was ground level how could this be hard to work out? What's the catch?

[Sprouts]

i can only work these thing out in wool

[hugoagogo]

oh never mind

just that you don't need to do anything with the original radius, converting miles to inches etc

it's just pi x 24

[Marf]

mybrainhurts said:

How long is a piece of string...?

Twice as long as it is from its end to its middle

[robinhood21]

Think it works out at something like 75.5 inches.

Extra that is.

Edited by robinhood21 on Monday 18th August 19:52

[bigfoot7]

24,901.55118999722 miles in total or only slightly more.

Or am I totally wrong?

I make it 75.39 inches.

Edited by bigfoot7 on Monday 18th August 19:57

[Bushmaster]

REPOST - I posted the exact same question about three years ago!! and still waiting for the right answer.

[bobthemonkey]

robinhood21 said:

Think it works out at something like 75.5 inches.

Extra that is.

Edited by robinhood21 on Monday 18th August 19:52

I concur. (well 75.4 inches)
Working
((24901.55/pi)+0.0003788[24 inches as miles])*pi