Drexel dragonThe Math ForumDonate to the Math Forum



Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.


Math Forum » Discussions » Math Topics » geometry.puzzles.independent

Topic: Cable around the Equator
Replies: 10   Last Post: Jun 17, 2012 2:29 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Alan Lipp

Posts: 41
Registered: 12/6/04
Re: Cable around the Equator
Posted: Nov 4, 1996 8:05 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply



On Mon, 4 Nov 1996, mfr1 wrote:

> Ma Bell want to place a telephone cable around the equator. She adds 50
> feet to the length of the cable beyond what is required. This slack in the
> cable allows the cable to be strung up above the ground. How high up from
> the surface of the earth will the cable stand? You can assume that the
> earth is a perfect sphere.
>
> In your mind, run a sanity check on your answer to see if it makes sense.
>

Surprisingly, you will be able to walk under the cble easilty. Since the
circumference of a circle is C = 2piR, each increase in R obf 1 foot
increases the circumference by 2pi feet. since the cable has been
increased by 50 feet the radius of the cable-circle will be increased by
50/2pi or about 8 feet!

Alan Lipp






Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2014. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.