Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**SuperLynx****Member**- Registered: 2009-06-28
- Posts: 321

That is another thread, please keep it separate

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 104,365

There is no keeping that separate.

Please read post #48. That information is required. is 2 digits after the decimal ( like the only measurement ) all you want?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

Offline

**SuperLynx****Member**- Registered: 2009-06-28
- Posts: 321

Yes, 2 digits after the decimal.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 104,365

Okay, thank you.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

Offline

Hi bobbym,

How will you calculate that without knowing the nature of the bent?

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,015

Post #34 contains the picture.

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 104,365

Yes, I will use the picture, it is already half done but there are still theoretical problems that the OP has not considered.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

Offline

What do you understand by height with a bend and height without a bend?

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 104,365

Height to the OP is 11.76 cm. The drawing is a little off but manageable.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

Offline

and how long is your kitchen?

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 104,365

Even I can not answer that question and I see it every day.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

Offline

you should fire up Mathematica.

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 104,365

That is a good idea but I would not torture Mathematica with that problem. It is ill posed.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

Offline

LucidLynx' problem is not well posed either

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 104,365

At present I would say that it is not.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

Offline

**SuperLynx****Member**- Registered: 2009-06-28
- Posts: 321

I'd like to know how you solve this?

Offline

I'd like to know why you want this problem to be solved

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 104,365

I'd like to know how you solve this?

I have not solved it yet so there is nothing to tell.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

Offline

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,588

hi bobbym,

While you're at it, please would you tell me how big my kitchen is. We're having new cupboards fitted and I need to know how many tiles we'll need.

Bob

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 104,365

Hi Bob;

Probably bigger than mine.

Hi SuperLynx;

As predicted problems popped up. I am getting 30.8 cm for the outside edge. The edge is marked in green with blue points. This is probably accurate to ± .1 ?!

The problem is the inside edge is obviously shorter. Can we really now talk about what the length of pipe would be if straightened out? I do not thinks so since the pipe would definitely crack when trying to straighten it.

If we talk about a hypothetical pipe we must decide which edge will be the length measured. I chose the longer edge because we get more pipe for our money.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

Offline

**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,015

I think there are physics equations that describe the state of objects under the deformation of bending. I'll look 'em up.

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

Offline

**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,015

Here's the Wiki page on Bending.

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 4,374

Hi,

Did some web research and found this (amongst other stuff about it):

1. Pipe generally distorts somewhat during the bending process (thus probably affecting the length of pipe needed), depending on factors such as:

(a) the pipe's wall thickness and tensile strength

(b) the bending tool and bending process

2. Less pipe length is required for a shallow bend than for a sharper bend (see image), so we'll need to know the bend dimensions, including the 'Centreline Radius' (CLR).

It seems to me that there are too many unknowns and variables for a precise calculation to be done on this problem.

Anyway, the solution can be found with reasonable accuracy using liquid, but before I divulge anything about it I'd like to pose this as a puzzle for someone to find the method.

*Last edited by phrontister (2013-11-26 09:25:17)*

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

Offline

**SuperLynx****Member**- Registered: 2009-06-28
- Posts: 321

What information would you need to make it easier to calculate, what the actual length of the pipe was before it was bent ?

Offline

Bobbym, Bob Bundy: My math teacher at school seems to be online now, maybe I should ask her about this question?

Hello Lucid Lynx;

We are posting paragraphs after paragraphs and all you have for us is an one line response?

0. **Try to read every post before you post and answer whatever they are trying to say**

1. Why do you want this to be calculated?

2. Can you post a real picture of it?

3. Explain what you mean by 'length of the pipe before it was bent'.

4. Explain what do you mean by measurement from 'top to bottom'

5. Explain what kind of a bent it is.

6. If the problem is from a textbook, give us the exact words of the problem and the diagram if any.

7. If possible make a video of what measurements you exactly want. If not, try to use a program like Geogebra or Sketchpad to draw legitimate diagrams of it.

8. **Please confirm that this is a real problem and not a riddle or a puzzler**

*Last edited by Agnishom (2013-11-22 05:38:31)*

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline