Jump to content


Welcome to BrainDen.com - Brain Teasers Forum

Welcome to BrainDen.com - Brain Teasers Forum. Like most online communities you must register to post in our community, but don't worry this is a simple free process. To be a part of BrainDen Forums you may create a new account or sign in if you already have an account.
As a member you could start new topics, reply to others, subscribe to topics/forums to get automatic updates, get your own profile and make new friends.

Of course, you can also enjoy our collection of amazing optical illusions and cool math games.

If you like our site, you may support us by simply clicking Google "+1" or Facebook "Like" buttons at the top.
If you have a website, we would appreciate a little link to BrainDen.

Thanks and enjoy the Den :-)
Guest Message by DevFuse
 

Photo
- - - - -

Round vs. Square


  • This topic is locked This topic is locked
41 replies to this topic

#31 thermalguru65

thermalguru65

    Newbie

  • Members
  • Pip
  • 9 posts

Posted 09 April 2008 - 01:07 PM

a round cover can never fall in.
  • 0

#32 Bambi Lynn

Bambi Lynn

    Newbie

  • Members
  • Pip
  • 1 posts

Posted 10 April 2008 - 11:31 AM

You guys!!! Any hole, whether round, square, triangular or whatever will allow the piece cut out of it to fall through, UNLESS there is a flange added at the bottom of the hole to keep the cover from falling in. Can't see where math in any form is usable here.
  • 0

#33 Alchameth

Alchameth

    Junior Member

  • Members
  • PipPip
  • 22 posts

Posted 10 April 2008 - 06:50 PM

Aside from the obvious 2 reasons listed safety and move ability you have to consider a few other reasons...

Weight distribution over a round hole is more constant where as anything with a corner would have pressure points and be overall weaker.

Materials, it is the most efficient use of materials for the shape and purpose compared to other shapes. Larger area with less materials.

Putting back and removing it, a circle doesn't care how you put it in, you would have to line up corners with other shapes, and if you were under a manhole you can push it up from any side vs. a cornered geometric shape having to make sure you "hinged" it on a flat side.
  • 0

#34 Duh Puck

Duh Puck

    Advanced Member

  • Members
  • PipPipPip
  • 445 posts

Posted 10 April 2008 - 07:13 PM

Any hole, whether round, square, triangular or whatever will allow the piece cut out of it to fall through, UNLESS there is a flange added at the bottom of the hole to keep the cover from falling in. Can't see where math in any form is usable here.

That's true, but even with the flange, shapes other than constant-width-diameter curves will still be able to fall through the hole. You have to assume that the maximum diameter of the cover includes the difference due to the flange, and the maximum diameter of the hole does not. Let's say it's a difference of 1 inch, and you have a square manhole cover 24 inches in width (and thus a hole 22 inches width). That still leaves you with a diagonal opening of over 31 inches, so flange or not, the square cover can easily fall through the hole. The "math" angle of the discussion is quite relevant.
  • 0

#35 Lost in space

Lost in space

    Senior Member

  • Members
  • PipPipPipPip
  • 4009 posts

Posted 11 April 2008 - 01:36 AM

can we do the bit about the whole truth, or the more you take away from it the bigger it gets, or pi, or can we say the gist of this is 'covered'
no more holes pls
  • 0

#36 That one girl...

That one girl...

    Junior Member

  • Members
  • PipPip
  • 36 posts

Posted 22 April 2008 - 07:34 PM

The obvious answer is that manhole covers should be round because manholes are round.

But your answer is more informative.


I agree. :D
  • 0

#37 Chuck Rampart

Chuck Rampart

    Advanced Member

  • Members
  • PipPipPip
  • 314 posts

Posted 23 April 2008 - 09:31 PM

Materials, it is the most efficient use of materials for the shape and purpose compared to other shapes. Larger area with less materials.


This really depends on what is going up and down the hole. If you're transporting boxes that are cube shaped, then of course it is most efficient to use a hole square in cross section. If you're moving spheres, then obviously the circular hole is the way to go. If you're moving something that is well approximated by a line of diameter as it passes through the hole - panes of glass, for instance, slid through vertically - then the most efficient shape is a Reuleaux Triangle . This shape has a constant diameter, so the pane of glass can be rotated (and the cover won't fall through) with the best ratio of diameter to area. This allows the least amount of material removal in digging the hole for a given size of glass.

For the other reasons mentioned, though, as well as the fact that a wide variety of people and loads probably need to go down manholes, a circle is the best option.
  • 0

#38 rockinsteady

rockinsteady

    Newbie

  • Members
  • Pip
  • 11 posts

Posted 15 May 2008 - 02:21 PM

:P if they were square they would fall down into the hole, also, so they can roll them since they are heavy.
  • 0

#39 kaleni-san

kaleni-san

    Newbie

  • Members
  • Pip
  • 12 posts

Posted 25 September 2008 - 01:55 PM

dudes ... you guys are like having a smarticles fight... freaky.PINK!
  • 0

#40 Claea

Claea

    Newbie

  • Members
  • Pip
  • 3 posts

Posted 22 October 2008 - 12:52 AM

I thought becauz men weren't square
  • 0




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users