# Physics Question of the day # 2
**URL:** https://forums.speedlife.net/t/physics-question-of-the-day-2/67513
**Category:** NYSpeed Off Topic
**Created:** [May 8, 2009, 2:06pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513 "2009-05-08T14:06:56Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@Viper966](https://forums.speedlife.net/u/Viper966)
#### Post date: [May 8, 2009, 2:06pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/1 "2009-05-08T14:06:56Z")
I am sitting in a boat in a swimming pool. There is a heavy rock in my boat. I carefully mark the water line on the tiles of the swimming pool. I then throw the rock over board. Will the water line go up, or down, or will it stay the same.
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### Author:  [@Pass\_McGass](https://forums.speedlife.net/u/Pass_McGass)
#### Post date: [May 8, 2009, 2:08pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/2 "2009-05-08T14:08:48Z")
What the fuck are you doing with a boat in a swimming pool?
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### Author:  [@tpgsr](https://forums.speedlife.net/u/tpgsr)
#### Post date: [May 8, 2009, 2:09pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/3 "2009-05-08T14:09:54Z")
The rock will slice the liner, you will be sitting in a boat in an empty pool, and your neighbors will be looking at you very oddly.
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### Author:  [@boardjnky4](https://forums.speedlife.net/u/boardjnky4)
#### Post date: [May 8, 2009, 2:11pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/4 "2009-05-08T14:11:13Z")
fuck you
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### Author:  [@97FormulaWS-6](https://forums.speedlife.net/u/97FormulaWS-6)
#### Post date: [May 8, 2009, 2:12pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/5 "2009-05-08T14:12:29Z")
what’s the density of the rock?
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### Author:  [@brent\_strong](https://forums.speedlife.net/u/brent_strong)
#### Post date: [May 8, 2009, 2:12pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/6 "2009-05-08T14:12:37Z")
Down, fggt. Mass displacement vs volume displacement.
Unless you’re playing with pumice or something fruity like that. I’m assuming the rock is pretty dense.
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### Author:  [@theblue](https://forums.speedlife.net/u/theblue)
#### Post date: [May 8, 2009, 2:26pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/7 "2009-05-08T14:26:49Z")
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### Author:  [@pirite](https://forums.speedlife.net/u/pirite)
#### Post date: [May 8, 2009, 2:33pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/8 "2009-05-08T14:33:23Z")
> [@tpgsr](#):
>
> The rock will slice the liner, you will be sitting in a boat in an empty pool, and your neighbors will be looking at you very oddly.
:bigclap:
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### Author:  [@Viper966](https://forums.speedlife.net/u/Viper966)
#### Post date: [May 8, 2009, 2:54pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/9 "2009-05-08T14:54:28Z")
> [@theblue](#):
>
> 
Touche
Only OG will get this
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### Author:  [@LZ1](https://forums.speedlife.net/u/LZ1)
#### Post date: [May 8, 2009, 2:59pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/10 "2009-05-08T14:59:57Z")
:lol:@ Pumice
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### Author:  [@2TurboZ](https://forums.speedlife.net/u/2TurboZ)
#### Post date: [May 8, 2009, 3:11pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/11 "2009-05-08T15:11:39Z")
Pumice T pic nails the thread save!
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### Author:  [@ultradriver10000](https://forums.speedlife.net/u/ultradriver10000)
#### Post date: [May 8, 2009, 5:10pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/12 "2009-05-08T17:10:14Z")
> [@brent\_strong](#):
>
> Down, fggt. Mass displacement vs volume displacement.
>
> Unless you’re playing with pumice or something fruity like that. I’m assuming the rock is pretty dense.
+1 woooooord
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### Author:  [@Willybeen](https://forums.speedlife.net/u/Willybeen)
#### Post date: [May 8, 2009, 5:17pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/13 "2009-05-08T17:17:38Z")
AMAZING responses… lol @ pumice and all the other comments
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### Author:  [@Willybeen](https://forums.speedlife.net/u/Willybeen)
#### Post date: [May 8, 2009, 5:24pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/14 "2009-05-08T17:24:33Z")
too many unknowns…
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### Author:  [@LAFENGAS](https://forums.speedlife.net/u/LAFENGAS)
#### Post date: [May 8, 2009, 6:21pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/15 "2009-05-08T18:21:24Z")
water line will go down because the while the rock is in the boat…the boat displaces the rocks weight, which is assumed to have a higher specific gravity than water (assuming the rock sinks in water). the amount of water that’s displaced by the rocks weight is greater then the rocks volume.
when the rock is in the water, only the volume of the rock is displaced, therefore the water line will go down.
a sheep will float.
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### Author:  [@pirite](https://forums.speedlife.net/u/pirite)
#### Post date: [May 8, 2009, 6:42pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/16 "2009-05-08T18:42:48Z")
> [@LAFENGAS](#):
>
> water line will go down because the while the rock is in the boat…the boat displaces the rocks weight, which is assumed to have a higher specific gravity than water (assuming the rock sinks in water). the amount of water that’s displaced by the rocks weight is greater then the rocks volume.
>
> when the rock is in the water, only the volume of the rock is displaced, therefore the water line will go down.
>
> a sheep will float.
+karma for the only real and actual answer
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### Author:  [@Willybeen](https://forums.speedlife.net/u/Willybeen)
#### Post date: [May 8, 2009, 6:50pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/17 "2009-05-08T18:50:13Z")
ok, lets say you had a lead ball that was 2ft in diameter it weighed 200 lbs… and you had the same size ball made of aluminum… it weighed 5 lbs… both would sink and displace the same amount of water when thrown overboard… assuming they didnt land outside of the pool :lol:, however, when in the boat, the amount of mass that the said balls have would NOT displace a the same amount of water.
therefore it depends on mass/density/ etc etc… multiple variables.
right?
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### Author:  [@RedGoober4Life](https://forums.speedlife.net/u/RedGoober4Life)
#### Post date: [May 8, 2009, 8:25pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/18 "2009-05-08T20:25:28Z")
Lead is now 40 times more dense than aluminum?
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### Author:  [@Blue\_Eyed\_Devil](https://forums.speedlife.net/u/Blue_Eyed_Devil)
#### Post date: [May 8, 2009, 9:27pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/19 "2009-05-08T21:27:33Z")
^No the aluminum ball is hollow. 😃
(Of course then it might float.)
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### Author:  [@Motocrossx23](https://forums.speedlife.net/u/Motocrossx23)
#### Post date: [May 8, 2009, 9:40pm UTC](https://forums.speedlife.net/t/physics-question-of-the-day-2/67513/20 "2009-05-08T21:40:48Z")
Lead weighs whatever the hell it wants.
I just built a 12ft canoe, no joke. I say we test this in someones pool.
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