Which is heavier-- a pound of lead or a pound of feathers?

[ginkgo]

Have you figured out the answer? Actually it was an old joke based on how people mis-hear things. People start thinking about the density (weight per volume) of the 2 things but they both weigh the same.

OK, fun time over. Which weighs more-- a pound of lead or a pound of gold? This is a real question. Also which weighs more-- an ounce of lead or an ounce of gold? Could the 2 questions have different answers? Also which one is more dense since this is what people think about with the lead and feathers?

Can gold be twice as heavy as lead? Of course that is an invalid question. Can gold be twice as dense as lead meaning that with a piece of each the same size, the gold one weighs twice as much as the lead one? Lastly which one would you rather get for Christmas/Hannukah or Kwanza?

For entertainment here are answers of different people. Whitch is heavier lead or gold? - Yahoo! Answers Note that one guy is saying that gold is the most valuable metal. Platinum and palladium are more precious than gold. In the movie Back to the Future, McFly was asking a woman out and said "it is our density", then corrected it to "destiny".

Also one more having to do more with nutrition. "Kilo" means 1,000 like a kilometer is 1,000 meters. Did you know that a kilocalorie is the same as a calorie. Don't shoot the messenger. I did not invent this confusion. Maybe some people created this stuff while drunk. See Wikipedia!

[Daffy Duck]

If you're talking about pure weight, then one pound is one pound, so they both would weigh the same.

It seems you have a different answer in mind though. Go ahead and share it. You love your technicalities.

[aelle]

A pound is a unit of mass, not of weight.
A kilocalorie is 1000 calories, but the everyday use has abbreviated it into 'calorie', just like 'a kilo' is the abbreviation of 'a kilogram'.

[WhiteCrow]

Originally Posted by ginkgo

Also one more having to do more with nutrition. "Kilo" means 1,000 like a kilometer is 1,000 meters. Did you know that a kilocalorie is the same as a calorie. Don't shoot the messenger. I did not invent this confusion. Maybe some people created this stuff while drunk. See Wikipedia!

Isn't kcal 1000 cal, but people just using calories but mean kcalories?

Years ago when I started training, the threadmill at the gym would show how much calories I was burning per hour. It was like 500 or something. I asked the guy at the gym whether it was 500 cal or 500 Kcal, not knowing what it was.

He said ofcourse CAL. And I was like WTF, do I have to work for an hour just to burn THAT little!!!???? It freaked me out

[WhiteCrow]

Originally Posted by aelle

A pound is a unit of mass, not of weight.
A kilocalorie is 1000 calories, but the everyday use has abbreviated it into 'calorie', just like 'a kilo' is the abbreviation of 'a kilogram'.

Damn you beat me :P

Oh and by the way, the yahoo link is HILARIOUS.

P.S

I think a pound of feathers is heavier than a pound of lead. The center of gravity is probably farther away when you try to lift it :P

[Daffy Duck]

Originally Posted by aelle

A pound is a unit of mass, not of weight.

My dictionary states that a pound is: a unit of weight and of mass, varying in different periods and countries.

So... we'll take that for what it's worth.

This topic doesn't seem to be about health or fitness, yet, but I don't see any other sub-forum where it would be more appropriate either. How tricky.

[ginkgo]

How many ounces are in a pound? The link that I gave shows that some people know the difference between a pound of lead and a pound of gold. Have you ever in your life ever heard the word "avoirdupois"? I did not make it up! It must be from French-- advoir-dupois.

That is the system (avoirdupois weight) that you weigh yourself and lead in. Gold is weighed in troy weight as are other precious metals. They are different. There are 10 ounces in a pound in troy weight. So the troy ounce is heavier than the avoirdupois ounce. But the troy pound is lighter since it is only 10 ounces.

[Daffy Duck]

If you want to get really technical, sure, it depends on how you're weighing it. But if we took a basic scale (like one used to weigh food) and put gold and lead into it, one pound is going to be one pound.

I have a new topic idea. "Is the thumb really a finger?"

[aelle]

Originally Posted by Daffy Duck

If you want to get really technical, sure, it depends on how you're weighing it. But if we took a basic scale (like one used to weigh food) and put gold and lead into it, one pound is going to be one pound.

Except that, no A scale will determine a weight (in Newtons) and convert it into kilograms (or pounds or whatever other silly unit) assuming that you are at sea level on a soil of average density. Weight depends on the gravity, mass doesn't.
That's if you use a numerical scale. Obviously if you use a balance with weighing pans, the weight of your references is going to vary in the same proportions than the weight of the objects you are trying to measure so gravity variations won't matter.

[ginkgo]

Originally Posted by aelle

A pound is a unit of mass, not of weight.

That is incorrect. But since you introduced the two (mass and weight), can you explain the difference between the two without looking it up and quoting something? Something that weighs a 100 kilograms on earth is weightless in space. So if a football and a battleship are in space then both are weightless.

But they have inertia which is the tendency to stay the same whether it is moving or still. So a little force moves the football if it is still and if it hits you in space going 20 miles per hour it will not push you much. But to get a still battleship moving requires lots of force. So mass is like assigning a weight to something that has no weight in space. So something with a mass of 100 kilograms in space is weightless in space but would weigh 100 kilograms on the earth.

As far as health and nutrition section, dealing with these different things requires a little understanding of science. A misunderstanding of science will cause a misunderstanding of different things in health and nutrition. Like for example a guy put up a post on this forum about the calories on a label under Total Calories and under Fiber. He got many resposnses but no one answered his question. They did not know what he was talking about.

If there is 5 grams of dietary fiber under total calories, those 5 grams of carbs, give you no calories. Why? Because fiber (which is a carb) cannot be digested. So how do they figure out that the fiber has 5 grams of carbs which is equal to 20 calories if my math is correct? They burn it! Calories are units of heat.

[ginkgo]

Originally Posted by Daffy Duck

If you want to get really technical, sure, it depends on how you're weighing it. But if we took a basic scale (like one used to weigh food) and put gold and lead into it, one pound is going to be one pound.

I have a new topic idea. "Is the thumb really a finger?"

Well you did not create the lead and gold out of thin air. You need to buy it if you live in a place that uses money. So you buy a pound of lead and they give you an advoirdupois pound. If it is not that, then they are committing fraud. Then you buy a pound of gold and it is a troy pound. If not, then they are committing fraud.

Then you take them home and put them on the scale. Your scale shows that the pound of lead is heavier than the pound of gold. The pound of gold weighs less than a pound on your scale. So you go to the gold dealer and tell him that he ripped you off and shoot him dead. Then you spend the rest of your life in prison. Or in Texas, you are executed. So knowing this can save your life.

"You love your technicalities." If you are on trial for your life, you can get off and be a free, innocent person on a technicality.

[aelle]

Originally Posted by ginkgo

That is incorrect. But since you introduced the two (mass and weight), can you explain the difference between the two without looking it up and quoting something?

Of course I can. You realize you're talking to a mechanical engineer?
A mass is an inherent characteristic of an object. SI unit: kilogram. An object that has a mass of 100 kilograms will always have a mass of 100 kg, wherever it is. it's an inertial property defined by the acceleration that will result form the action of an external force. The bigger the mass, the more force you need to apply to obtain the same acceleration.
A weight is the force created by a mass in a given gravitational field. SI unit: Newton. An object of a given weight on New York ground will have a slightly smaller weight at the top of the Empire State building, since gravity varies with altitude. Its weight will be even smaller in orbit or in space. Its mass, in kg, will remain constant.

In everyday life, the variations of gravity have little importance, so we consider variations of weight negligible, which is why we tend to confuse mass and weight.

A misunderstanding of science will cause a misunderstanding of different things in health and nutrition

You crack me up.
The definition of calorie does not come from nutrition science, although it's been applied and made famous by it. A calorie is a unit of thermal energy ; it is the amount of energy needed to heat 1 gram of water by 1 degree Celcius. The unit used in nutrition is indeed the Kilocalorie (Kcal), that is the amount of energy required to heat Kilogram of water by 1 degree Celcius.

[James81]

Originally Posted by aelle

Of course I can. You realize you're talking to a mechanical engineer?
A mass is an inherent characteristic of an object. SI unit: kilogram. An object that has a mass of 100 kilograms will always have a mass of 100 kg, wherever it is. it's an inertial property defined by the acceleration that will result form the action of an external force. The bigger the mass, the more force you need to apply to obtain the same acceleration.
A weight is the force created by a mass in a given gravitational field. SI unit: Newton. An object of a given weight on New York ground will have a slightly smaller weight at the top of the Empire State building, since gravity varies with altitude. Its weight will be even smaller in orbit or in space. Its mass, in kg, will remain constant.

In everyday life, the variations of gravity have little importance, so we consider variations of weight negligible, which is why we tend to confuse mass and weight.

In all of my Engineering classes (civil engineer here ), we made a distinction between lb-m (pound-mass) and lb.

[James81]

Oh, and I also had some teachers refer to a "slug" as the english unit for mass.

Most of the time, however, lbs were assumed to mean weight (that is, mass x acceleration of gravity).

[Daffy Duck]

Originally Posted by ginkgo

"You love your technicalities." If you are on trial for your life, you can get off and be a free, innocent person on a technicality.

True, and also, a small technicality can be the reason you're put in jail for life. It really all depends, doesn't it?

Originally Posted by aelle

Except that, no A scale will determine a weight (in Newtons) and convert it into kilograms (or pounds or whatever other silly unit) assuming that you are at sea level on a soil of average density. Weight depends on the gravity, mass doesn't.

We're talking about two different things. I'm talking about a basic scale which would report a 5lbs. dumbbell as being the same weight as a 5lbs. bucket of water, or 5lbs. of gold, and so on. I could easily prove what I'm saying using this type of scale. Just give me some gold and lead and water.

You naturally, as a mechanical engineer, are taking it into a more detailed analysis. And computer engineer here, lol.

[James81]

Originally Posted by Daffy Duck

. And computer engineer here, lol.

Looks like we got our bases covered in this thread.

Let's all design some ♥♥♥♥.

[aelle]

Originally Posted by James81

In all of my Engineering classes (civil engineer here ), we made a distinction between lb-m (pound-mass) and lb.

Oh, ok, point taken. All my classes used metric system only

[jackfrost1031]

Working in a dual system (read: US) is a real pain in the ass.

Units of force:
lbf
N

Units of mass:
lbm
slug
kg

lbm/lbf is a stuid convention. They are equivalent units numerically. I also see "Net weight" listed as ounces (1/16th of a lb..) and then also in kilogram (mass!). Most people don't care or don't realize there is a difference I guess but it really cheeses me off.

[James81]

Originally Posted by jackfrost1031

Working in a dual system (read: US) is a real pain in the ass.

Units of force:
lbf
N

Units of mass:
lbm
slug
kg

lbm/lbf is a stuid convention. They are equivalent units numerically. I also see "Net weight" listed as ounces (1/16th of a lb..) and then also in kilogram (mass!). Most people don't care or don't realize there is a difference I guess but it really cheeses me off.

If I remember right, lbm and lbf are actually the same number so long as you are on earth.

Then again, it's been a long time since I've studied that stuff.

[Barcs]

Since I like to keep things simple, 1 pound = 1 pound = 1 pound = 1 pound. Whether it's feathers, lead, gold, or dog doo. As long as you are using an exact scale on planet earth with the same measurements in the same location it will weigh the same. Since the question specifically says "weigh", it has nothing to do with mass or density. It will still weigh the same regardless of it's center of gravity or density. The only difference would be if you were to weigh it on a different planet, and quite possibly even from a higher or lower altitude. Same location = same weight, nomatter where you weigh it from though.. Ok I tried to keep it simple lol.

[ginkgo]

Originally Posted by Barcs

Since I like to keep things simple, 1 pound = 1 pound = 1 pound = 1 pound. Whether it's feathers, lead, gold, or dog doo. As long as you are using an exact scale on planet earth with the same measurements in the same location it will weigh the same. Since the question specifically says "weigh", it has nothing to do with mass or density. It will still weigh the same regardless of it's center of gravity or density. The only difference would be if you were to weigh it on a different planet, and quite possibly even from a higher or lower altitude. Same location = same weight, nomatter where you weigh it from though.. Ok I tried to keep it simple lol.

Some people threw in a red herring like with mass. Density does not matter. You may like to keep it simple, but if you buy a pound of gold and weigh it, it will weigh less than a pound. If you complain, they will tell you that you used the wrong scale to weigh it on while calling you a stupid idiot.

A pound of gold is 10 ounces. A pound of lead is 16 ounces. An ounce of gold is 31 grams. An ounce of lead is 28 grams. GET IT, GOT IT, GOOD!

[Doku]

Originally Posted by ginkgo

Some people threw in a red herring like with mass. Density does not matter. You may like to keep it simple, but if you buy a pound of gold and weigh it, it will weigh less than a pound. If you complain, they will tell you that you used the wrong scale to weigh it on while calling you a stupid idiot.

A pound of gold is 10 ounces. A pound of lead is 16 ounces. An ounce of gold is 31 grams. An ounce of lead is 28 grams. GET IT, GOT IT, GOOD!

Since you are choosing to be a niggler here... there are 12 Troy ounces per Troy pound, not 10.

[Barcs]

Originally Posted by ginkgo

Some people threw in a red herring like with mass. Density does not matter. You may like to keep it simple, but if you buy a pound of gold and weigh it, it will weigh less than a pound. If you complain, they will tell you that you used the wrong scale to weigh it on while calling you a stupid idiot.

A pound of gold is 10 ounces. A pound of lead is 16 ounces. An ounce of gold is 31 grams. An ounce of lead is 28 grams. GET IT, GOT IT, GOOD!

Oh I get it. It's more of a marketing scheme. They say it's a pound, but can get away with selling less for the same price. That's messed up!!

[Dilman]

Originally Posted by aelle

A pound is a unit of mass, not of weight.
A kilocalorie is 1000 calories, but the everyday use has abbreviated it into 'calorie', just like 'a kilo' is the abbreviation of 'a kilogram'.

Actually, a pound is a measure of weight, and grams are a measure of mass.

[Daffy Duck]

Dictionary.com defines a "gram" as a metric unit of mass or weight.

All these lovely semantics...

[Brutha]

You naturally, as a mechanical engineer, are taking it into a more detailed analysis. And computer engineer here, lol.

Then how much bit do fit in one kilobyte?
I hate those harddrive companies...

[Daffy Duck]

One kilobyte is 8192 bits. Why do you hate them?

[James81]

Originally Posted by Dilman

Actually, a pound is a measure of weight, and grams are a measure of mass.

Nah, the english unit for mass is a "slug", not a gram.