All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Science
Alien Messages (Posted on 2007-01-23) Difficulty: 3 of 5
In another solar system there exists a planet approximately the size of Earth. This planet is a solid sphere of uniform density.

The inhabitants send messages to each other by placing the message in a capsule and placing the capsule in a message tube. These message tubes are straight lines through the planet from one point on the surface to another.

A capsule moves through a tube only under the influence of gravity (no friction force between the capsule and the tube and no forces due to the planet's rotation).

What is the ratio between the time it takes to send a message from the North Pole to the South Pole and the time it takes to send a message from the South Pole to the Equator?

Note: The gravitational effects of the message tubes are negligible compared to the gravitational effects of the planet.

Note: Assume a mechanism at each end of a message tube to catch an incoming capsule (easy to do since the velocity will be zero).

See The Solution Submitted by Bractals    
Rating: 2.5000 (4 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
re: from general knowledge (spoiler) | Comment 2 of 4 |
(In reply to from general knowledge (spoiler) by Charlie)

If so then the situation is akin to a pendulum.  The period is independant of the height of the swing.

What one could possibly do is show that the forces work in the same way.


  Posted by Jer on 2007-01-24 11:51:48
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (4)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2017 by Animus Pactum Consulting. All rights reserved. Privacy Information