Author |
Topic: Purple rain (Read 658 times) |
|
alien
Guest
|
It raines. There is the swimming pool near the house in the form of a cube, with the side 10 meters long. All rain drops fall in exactly one second sequence of time, perpendicullary, and 1 centimeter apart from one another. Those drops nearest to the edge of the swimming pool fall 5 millimeters off the edge. What time is needed for the pool to be full to the brink, if each rain drop containes the volume of 2 cubic millimeters?
|
|
 IP Logged |
|
|
|
Grimbal
wu::riddles Moderator
Uberpuzzler
Gender: 
Posts: 7527
|
 |
Re: Purple rain
« Reply #1 on: Feb 24th, 2005, 5:16am » |
 Quote  Modify
|
Rain is certainly strange on your planet, alien.
- On your planet, do the rain drops fall in a square grid or a triangular grid?
- How far is the swimming pool from the house?
- What about evaporation?
- Is the swimming pool empty at the start?
- Is the pool drain closed? (as you would expect if it is empty)
- Will the rain last for at least 5 days, 18 hours 53 minutes and 20 seconds ?
|
|
IP Logged |
|
|
|
SMQ
wu::riddles Moderator
Uberpuzzler
Gender:
Posts: 2084
|
|
Re: Purple rain
« Reply #2 on: Feb 24th, 2005, 5:24am » |
Quote Modify
|
If I understood that right :: every cm2 of area receives one 2mm3 drop per second, right? So every 1cm2x10m = 1,000,000mm3 column is "filled" in 500,000s = 5 days, 18 hours, 53 minutes and 20 seconds. ::
--SMQ
|
| « Last Edit: Feb 24th, 2005, 5:26am by SMQ » |
IP Logged |
--SMQ
|
|
|
towr
wu::riddles Moderator
Uberpuzzler
Some people are average, some are just mean.
Gender:
Posts: 13730
|
|
Re: Purple rain
« Reply #3 on: Feb 24th, 2005, 1:18pm » |
Quote Modify
|
on Feb 24th, 2005, 1:08pm, alien wrote:
Quote:"On your planet, do the rain drops fall in a square grid or a triangular grid?"
That's not important. |
|
It does rather substantially influence the answer, so I'd say it is important.
|
|
IP Logged |
Wikipedia, Google, Mathworld, Integer sequence DB
|
|
|
towr
wu::riddles Moderator
Uberpuzzler
Some people are average, some are just mean.
Gender:
Posts: 13730
|
|
Re: Purple rain
« Reply #4 on: Feb 25th, 2005, 12:46am » |
Quote Modify
|
Whether viewed from the top, the drops fall in this pattern:
o o o o o o o
o o o o o o o
o o o o o o o
o o o o o o o
o o o o o o o
o o o o o o o
or this one:
o o o o o o o
o o o o o o o
o o o o o o o
o o o o o o o
The first one has a higher density of drops, so the pool would be filled quicker (in about sqrt(3)/2 times the time)
|
| « Last Edit: Feb 25th, 2005, 12:47am by towr » |
IP Logged |
Wikipedia, Google, Mathworld, Integer sequence DB
|
|
|
alien
Guest
|
Now I understand. The second pattern is what I had in mind.
|
|
IP Logged |
|
|
|
|
RIDDLES SITE
WRITE MATH!
Home 
Help 
Search 
Members 
Login 
Register
Reply
Notify of replies
Send Topic
Print
Remove