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Physics question

Posted: May 30, 2003, 10:10 am
by Krimson Klaw
Co-workers are arguing about which weighs more, raw or hard boiled egg. I can't find the answer, if you can, paste a source please.

Posted: May 30, 2003, 10:22 am
by Acies
They weigh the same excepting minute amounts that are cooked off the hard boiled egg.

Posted: May 30, 2003, 10:24 am
by Krimson Klaw
Yea that's a given due to the shell not being very porous, we are trying to figure out which minute amount, is it more or less weight.

Posted: May 30, 2003, 10:29 am
by Acies
Most of it is in the yellow, proceeded by the white.
However when hard boiling, tiny pockets of air will catch themselves inside the white and yellows, making the cooked verison seem more light in water. In reality, the cooked verison is technically lighter, but only barely. I would say by maybe a mirco-ounce or two.
I have looked, cannot find any sites that verify what I am saying directly. Give me more time to research and I will find you "something" though

Posted: May 30, 2003, 10:33 am
by Fallanthas
Hard-boiled eggs are lighter.


An old trick for sorting them out after the kids put the groceries away......drop each egg in a glass of water. Floaters = hard-boiled. Raw eggs sink.

Posted: May 30, 2003, 10:42 am
by Voronwë
Krimson Klaw wrote:Yea that's a given due to the shell not being very porous, we are trying to figure out which minute amount, is it more or less weight.
egg shells are permiable to gas, so water vapor can leave.

i cant see why a hard boiled egg would weigh more.

the mass does not increase.
the inertial reference frame does not change (ie gravity)
therefore there is no way for the hardboiled egg to weigh more

F=ma

F is the force applied by gravity (weight)
m is the mass
a is gravitational acceleration

so there are only 2 possible answers


1. there is no water vapor that leaves during boiling, therefore no mass change, so no weight difference

2. some water vapor leaves during boiling (most likely scenario) so less mass, so less weight.

If Fallanthas' example is true, then scenario 2 is true.

d=m/v

the volume of the shell is static, so the only way for a density change (float or sink) is for the mass to change. So if boiling an egg makes it float, then the density has decreased through a decrease in mass.

the mass decrease must be from gas (water vapor most likely) escaping during cooking.

Posted: May 30, 2003, 10:43 am
by Phugg_Innay
Fall that doesnt tell you anything about wieght, just the density of the egg before and after. example: 4 ounce lead ball in a bucket of water will sink, while 4 ounces of plastic will float in the same space. Same thing can apply with your own body in fresh water , you sink , in salt water you float. that is because of the dendity of the water though , not you body.

Posted: May 30, 2003, 10:47 am
by Voronwë
Phugg_Innay wrote:Fall that doesnt tell you anything about wieght, just the density of the egg before and after. example: 4 ounce lead ball in a bucket of water will sink, while 4 ounces of plastic will float in the same space. Same thing can apply with your own body in fresh water , you sink , in salt water you float. that is because of the dendity of the water though , not you body.
density is related to weight because both vary directly with the mass of the object.

for the equation below F= force = weight
F=ma
d=m/V

d=F/(aV)

density is very dependent on the weight (F)

Posted: May 30, 2003, 11:11 am
by masteen
African or European eggs?

Posted: May 30, 2003, 11:13 am
by Canelek
Very small rocks!

Posted: May 30, 2003, 11:13 am
by miir
masteen wrote:African or European eggs?
African swallow eggs

Posted: May 30, 2003, 11:17 am
by masteen
huh-huh... you said "swallow." huh-huh

Posted: May 30, 2003, 11:29 am
by Ennia
Source:
http://www.ci.carlsbad.ca.us/cserv/2kids4.html
Experiment #10 - Making an Egg Float
The objective of this activity is to learn how salt affects the buoyancy of water.

Materials: raw egg, hard-boiled egg, glass of water, salt, tablespoon

1.
Put the raw egg in the glass of water. Watch what happens. Take the raw egg out of the glass.

2.
Put the hard-boiled egg in the glass of water.

3.
Add salt, one tablespoon at a time, until something happens to the egg.

4.
Once you have finished with step 3, take out the hard-boiled egg and put the raw egg into the glass. What happens?


Salt makes the water heavier. As the salt water becomes heavier, the egg is able to float. The key to floating is that the object (the egg) has to weigh less than the water it displaces (takes the place of). Adding salt makes the water heavier, so eventually the egg weighs less than the salt water it displaces. The raw egg weighs less than the hard-boiled egg, so it can float in both the tap water and the salt water.

Posted: May 30, 2003, 12:24 pm
by Voronwë
not flaming you Ennia.

the person who wrote the experiment above is a fucktard.

it is not testing the 'buoyancy' of water. The test is to measure the buoyancy of the egg or the density of the water. But to use more parsinomious language, the relative density of both.

Not the weight.

anyways, considering the author does not even understand what he or she is trying to test, i am not going to accept the conclusions as reliable.

but i did some searching and found that some kindergarten class in Ohio found that raw and hard boiled eggs "weighed about the same" doing the salt water test described above.

of course that is a crock of shit too, because if you want to accurately weigh something use a scale, not a kindergartner, a glass of water, and a few spoonfulls of an unknown amount of salt :p

Posted: May 30, 2003, 4:18 pm
by Jice Virago
When the egg is boiled, the water (now in gaseous form) is able to escape through the porous egg shall exactly as Vor described. At this point the internal egg essentially becomes an emultion (specifically a foam) which is a hybrid of two states, specifically the egg is solid but there are tons of air pockets mixed in homogeniously. Once the egg is boiled, it has less mass and its density is less than that of liquid water. Prior to this the composition of the egg is mostly water and its mass is just greater enough to cause it to sink.

Hope this helps.

Posted: May 30, 2003, 4:33 pm
by Winnow
Jice Virago wrote:When the egg is boiled, the water (now in gaseous form) is able to escape through the porous egg shall exactly as Vor described. At this point the internal egg essentially becomes an emultion (specifically a foam) which is a hybrid of two states, specifically the egg is solid but there are tons of air pockets mixed in homogeniously. Once the egg is boiled, it has less mass and its density is less than that of liquid water. Prior to this the composition of the egg is mostly water and its mass is just greater enough to cause it to sink.

Hope this helps.
While I usually give Jice high marks for paragraph structure, the second paragraph in this case is kind of weak!

Why hasn't VV had a discussion regarding the physics of Winona Ryder's ping pong trick?

Posted: May 30, 2003, 4:39 pm
by Fallanthas
Fall that doesnt tell you anything about wieght, just the density of the egg before and after.

Unless the volume of the egg also changes, density = weight in close enough approximation to answer the question above.


Egg of a given size sinks in water.

Boil egg.

Egg (still of same size) now floats.

Unless you can show that the volume of the egg has increased, it HAS to have lost weight in order for this to happen.

Posted: May 30, 2003, 4:39 pm
by Truant
Winnow wrote:
Jice Virago wrote:When the egg is boiled, the water (now in gaseous form) is able to escape through the porous egg shall exactly as Vor described. At this point the internal egg essentially becomes an emultion (specifically a foam) which is a hybrid of two states, specifically the egg is solid but there are tons of air pockets mixed in homogeniously. Once the egg is boiled, it has less mass and its density is less than that of liquid water. Prior to this the composition of the egg is mostly water and its mass is just greater enough to cause it to sink.

Hope this helps.
While I usually give Jice high marks for paragraph structure, the second paragraph in this case is kind of weak!

Why hasn't VV had a discussion regarding the physics of Winona Ryder's ping pong trick?
because there is no question or confusion on how it works?

Posted: May 30, 2003, 4:49 pm
by Winnow
Truant wrote:
Winnow wrote:
Jice Virago wrote:When the egg is boiled, the water (now in gaseous form) is able to escape through the porous egg shall exactly as Vor described. At this point the internal egg essentially becomes an emultion (specifically a foam) which is a hybrid of two states, specifically the egg is solid but there are tons of air pockets mixed in homogeniously. Once the egg is boiled, it has less mass and its density is less than that of liquid water. Prior to this the composition of the egg is mostly water and its mass is just greater enough to cause it to sink.

Hope this helps.
While I usually give Jice high marks for paragraph structure, the second paragraph in this case is kind of weak!

Why hasn't VV had a discussion regarding the physics of Winona Ryder's ping pong trick?
because there is no question or confusion on how it works?
I'm baffled! Please explain! bok bok!

Posted: May 30, 2003, 7:25 pm
by Jice Virago
Weight is unimportant for boyancy. Density is all that matters. Specifically, an object can way thousands of pounds and still float or can just as easily weigh a few grams and sink. For the sake of argument the eggs volume remains basically unchanged, but its mass (and therefor density) are reduced when the water vapor escapes in the process of boiling it.

So we are clear on definitions here:

Mass = physical amount of matter of the object. As long as no matter is added or removed from an object, this is always a constant.

Weight = Mass x the local acceleration of gravity (basically a constant on earth as long as you maintain the same altitude)

Volume = The physical dimentions of an object. This can vary tremendously due to outside stimuli, but for the egg example it is a constant (assuming the shell remains intact)

Density = ratio of an objects mass to its volume. The more mass per unit of volume, the greater an ojects density. This is a constant as long as mass and volume remain constant (or at least the ratio remains the same). In liquid or gaseous environments, substances more dense than the primary medium will sink while those less dense will rise. In the case of this discussion, the unboiled egg is more dense than liquid water UNTIL the water escapes it leaving it a foamy substance less dense than the same water.

Blech. Thats a lot of high school physics jargon to explain a simple thing. Hope that answers all questions.

Posted: May 31, 2003, 7:10 am
by emmer
Ennia wrote:Source:
http://www.ci.carlsbad.ca.us/cserv/2kids4.html
Experiment #10 - Making an Egg Float
The objective of this activity is to learn how salt affects the buoyancy of water.

Materials: raw egg, hard-boiled egg, glass of water, salt, tablespoon

1.
Put the raw egg in the glass of water. Watch what happens. Take the raw egg out of the glass.

2.
Put the hard-boiled egg in the glass of water.

3.
Add salt, one tablespoon at a time, until something happens to the egg.

4.
Once you have finished with step 3, take out the hard-boiled egg and put the raw egg into the glass. What happens?


Salt makes the water heavier. As the salt water becomes heavier, the egg is able to float. The key to floating is that the object (the egg) has to weigh less than the water it displaces (takes the place of). Adding salt makes the water heavier, so eventually the egg weighs less than the salt water it displaces. The raw egg weighs less than the hard-boiled egg, so it can float in both the tap water and the salt water.
I used to live in that town... carlsbad, ca. It's actually pretty small, there is only one jr. high and only one high school, and I went to both... and I never did that experiment!

I call bullshit.