Calculate the height of the tortoise

[PhilTheFragger]

I think we should just agree to end the thread here and shell-ebrate the fact that the OP has caused so much mass debate.

Fixed it for ya

 

[SocketRocket]

Can we have the two ropes question next, please?
One all the way around the earth and the other one metre above the first one all the way round the earth. How much longer is the longer one?

To make it easy.
The earth has a diameter of 12,742 kilometres for the purpose of this question and can be represented as a circle rather than its true oblate spheroid shape.

Its one of my favourites.

View attachment 57348

A midges widger?

 

[KenL]

2pi

 

[Backache]

2pi

Surely there has to be a dimension?
2pi metres.

 

[Slab]

There's a couple of giant tortoises at the golf club (behind 15th green if you're looking for them) so when I went up for practice this morning I thought I'd just do the practical measure with one on ground and on the wall etc...



.... Couldn't catch one, slippery little devils, sorry folks

 

[backwoodsman]

There's a couple of giant tortoises at the golf club (behind 15th green if you're looking for them) so when I went up for practice this morning I thought I'd just do the practical measure with one on ground and on the wall etc...



.... Couldn't catch one, slippery little devils, sorry folks

But how you do know if the problem involves giant tortoises? It might just be a very tiny rock ?

 

[Slab]

But how you do know if the problem involves giant tortoises? It might just be a very tiny rock ?

My plan was to just stand a wee bit further away from them when I measured

 

[Mudball]

How did the turtle/tortoise get on top of that rock. How long did it take to get there? Where is its mate the hare?

The maths is simple and this has been on Twatter a few times.. but the philosophical debate is more nuanced

 

[rulefan]

2pi

2𝜋r

 

[Beezerk]

2𝜋r

Steak and kidney?

 

[Hobbit]

2𝜋r - bisto

 

[KenL]

2𝜋r

I said 2pi (in what ever unit you are using) as the extra length required in the rope for the rope to be uniformly 1 unit above the circumference of the circular object, in this case the Earth.
So for the rope to be 1m above the earth all the way around (assuming it to be perfectly circular) it only needs to be 6.28… metres longer that one that is a snug fit.

Astonishing when the Earth has a circumference of about 40 000 000 metres.

This number holds true for circles of all sizes.

 

[Voyager EMH]

I said 2pi (in what ever unit you are using) as the extra length required in the rope for the rope to be uniformly 1 unit above the circumference of the circular object, in this case the Earth.
So for the rope to be 1m above the earth all the way around (assuming it to be perfectly circular) it only needs to be 6.28… metres longer that one that is a snug fit.

Astonishing when the Earth has a circumference of about 40 000 000 metres.

This number holds true for circles of all sizes.

Yep.
The point of the question is that working out (two pi r) for the circumference of the earth in metres would involve a calculation of huge figures. Then a similar calculation for the longer rope, and then subtracting one from the other. The large numbers involved seems a big task - but this method is unnecessary.
A string around a golf ball and another string one metre above the surface of the golf ball gives the same result as using the earth's measurements.
The large numbers is the distraction in this question.

In the tortoise and rock question, the distraction is the childish cartoon pictures - that can lead one to look for a simple calculation as an answer.
It merely requires a more careful look.
When done with line-drawn shapes and measurements only, fewer hasty mistakes are usually made.

The mathematician Charles Dodgson (Lewis Carroll) was fond of this type of puzzle and created many of his own.

 

[KenL]

Yep.
The point of the question is that working out (two pi r) for the circumference of the earth in metres would involve a calculation of huge figures. Then a similar calculation for the longer rope, and then subtracting one from the other. The large numbers involved seems a big task - but this method is unnecessary.
A string around a golf ball and another string one metre above the surface of the golf ball gives the same result as using the earth's measurements.
The large numbers is the distraction in this question.

In the tortoise and rock question, the distraction is the childish cartoon pictures - that can lead one to look for a simple calculation as an answer.
It merely requires a more careful look.
When done with line-drawn shapes and measurements only, fewer hasty mistakes are usually made.

The mathematician Charles Dodgson (Lewis Carroll) was fond of this type of puzzle and created many of his own.

Great post.

 

[hambugerpete]

Another troll trick.

The thread title says "height of the tortoise" but the picture shows a question mark showing the distance from the ground to the top of the tortoise as its shown in the picture. Obviously the answer is 30cm.

Oh he's left

 

[Voyager EMH]

Oh he's left

Oh, he left?

 

[KenL]

Oh he's left

Who was that @hambugerpete ?

 

[hambugerpete]

Who was that @hambugerpete ?

Esat902010

 

[Voyager EMH]

Esat902010

I'll miss him.

 

[Imurg]

I'll miss him.

You may...but over time your aim will get better....