PDA

View Full Version : Physics puzzler


ouch
07-20-2006, 03:54 PM
You're out on a lake in your rowboat. The water is so still that you decide to shave, so you whip out your Merkur Vision. Unfortunately, it slips out of your hand and falls overboard.

So........

does the water level of the lake go up or down?:001_rolle
jmhUT
07-20-2006, 04:01 PM
Interesting.... On the one hand you have added mass to the lake which would make the water level go up. On the other hand, the boat is now lighter and not exerting as much pressure on the water's surface, which would allow the water line to receed.

Ultimately I believe that the water level was impacted when you entered the water in your boat with your razor. The razor relocating from inside the boat to the bottom of the lake would not effect the water level.

Totalling pulled that out of left field, am I close?
Cheers,
Jeff
moses
07-20-2006, 04:06 PM
The water level would go down.

When your vision was in the boat, it was displacing it's weight in water (Or rather, causing the boat to displace it's weight in water).

When you drop it overboard, the boat will no longer be displacing that water. On the other hand, the razor will be displacing water on its own now. But now it will be displacing its volume. Since it is heavier than water, this will be a smaller volume. Therefore the level in that lake will be going down slightly, because ever tiny a bit less water is being displaced.



Cold shave.... Ugg....
Tito
07-20-2006, 04:28 PM
The water goes down!

Cause I'm gonna open the spillway to get my razor back.
NMMB
07-20-2006, 04:30 PM
Considering that it is a "lake" that probably maens that there is a significant volume of water in this body. BrainyDictionary (http://www.brainydictionary.com/) defines a lake as "A large body of water contained in a depression of the earth's surface, and supplied from the drainage of a more or less extended area". So, where was I? Oh yeah, a lake is big... and given that a lake is "big" I doubt that you have any tool that is sufficiently precise so as to measure any difference in water level be it an increase or a decrease... thus making the answer to the question a moot point (if we can't measure it, who cares).

The more important question is, "how the heck are you going to find that razor on the bottom of a lake?"
jmhUT
07-20-2006, 05:04 PM
Considering that it is a "lake" that probably maens that there is a significant volume of water in this body. BrainyDictionary (http://www.brainydictionary.com/) defines a lake as "A large body of water contained in a depression of the earth's surface, and supplied from the drainage of a more or less extended area". So, where was I? Oh yeah, a lake is big... and given that a lake is "big" I doubt that you have any tool that is sufficiently precise so as to measure any difference in water level be it an increase or a decrease... thus making the answer to the question a moot point (if we can't measure it, who cares).

The more important question is, "how the heck are you going to find that razor on the bottom of a lake?"

He he, argued like a true economist:tongue_sm
mrob
07-20-2006, 05:50 PM
Its a trick question: Ouch has a rubber band on his Vision so it would never slip out of his hand!:tongue:
AceHarddrive
07-20-2006, 05:58 PM
My question is: What kind of a nut takes a razor in a rowboat out on a lake? Don't tell me he's got shaving cream, aftershave and moisturizer there as well?

~Tim :rolleyes:
JAG
07-20-2006, 06:50 PM
I thought a 'professional' economist would answer: "What do you want it to be?" and if a sufficiently clear response wasn't forthcoming he would go on two imcomprehesible rants separated with "On the other hand . . ."


Bob
Harkonnendog
07-20-2006, 06:56 PM
Roosters don't lay eggs!
TraderJoe
07-20-2006, 07:04 PM
I thought a 'professional' economist would answer: "What do you want it to be?" and if a sufficiently clear response wasn't forthcoming he would go on two imcomprehesible rants separated with "On the other hand . . ."


Bob

:lol: :lol: :lol:

so true
rtaylor61
07-20-2006, 07:31 PM
I believe the heat wave is beginning to take it's toll...

Randy
ouch
07-20-2006, 07:35 PM
Well, at least no one argued with moses, who got it right and expained it fairly well.
:thumbup1:
NMMB
07-21-2006, 06:29 AM
I thought a 'professional' economist would answer: "What do you want it to be?" and if a sufficiently clear response wasn't forthcoming he would go on two imcomprehesible rants separated with "On the other hand . . ."


Bob

I guess it has something to do with me being a more theoretical economist than an analytical economist... so long as things can't be measured then all that I can do is think and theorize about them... when they are measurable, however, is when things get complicated and I try to delegare the arduous analytical work to somebody else. :biggrin:
AACJ
07-21-2006, 06:42 AM
The water will rise when my fat ass jumps into the lake to get my razor.


The empty boat, after I have jumped in, does not take up as much mass in the water as I would compared to me being IN the boat and not in the water.
Tito
07-21-2006, 07:12 AM
The water will rise when my fat ass jumps into the lake to get my razor.


The empty boat, after I have jumped in, does not take up as much mass in the water as I would compared to me being IN the boat and not in the water.


:lol: That's what I'm talking about!
htownmmm
07-21-2006, 01:40 PM
My question is: What kind of a nut takes a razor in a rowboat out on a lake? Don't tell me he's got shaving cream, aftershave and moisturizer there as well?

~Tim :rolleyes:

The kind of nut who owns more than 2 razors, soaps, creams ,brushes, err,ummm, I resemble that remark.




Marty