What does 100 tons of concrete weight

[Al - s/v Persephone]

About 1,500,000 lbs, if it's Gross Tons (100 cu-ft per GRT, at 150lbs per cu-ft)

(We now return you to your regularly scheduled physics debate).

Fair winds,
Al - s/v Persephone

 

[Hermit Scott]

Haven't you heard the phrase "weightless in space"? Things have mass with out gravity, but with out gravity they have no weight.
If I am ever in doubt about what I am dealing with, be it statics and dynamics or heating and AC, I always look at the dimensions of what I am dealing with. It's called dimensional analysis.
With this weight-force scenario it does take some discussion in the classroom for everyone to get on board. I still don't remember what a pound is compared to a pound force. I do remember the differnece between a Kg and a newton though. And that is the difference between mass and weight(force).
When someone says "it weighs 5 Kgs". We know what they mean but they are technically wrong. They mean it weighs 5kg. at the surface of the earth. Whcih is really measured in newtons. Kgs have no force component in the dimensions.

 

[Rick Webb]

14285.714 Stone

What happens to the volume of a dime bag in space?

 

[MoonSailer]

http://en.wikipedia.org/wiki/Newton_(unit)

Hermit weight is a force. A newton is a unit of force. Mass is not a force it is a way to measure matter. More mass means more matter. Gravity is an acceleration and the amount of force depends upon the amount of mass being accelerated. Also remember the speed of acceleration in a vaccum is independent of the mass or density of the object. That is not perfectly true in that gravity depends upon both objects. But in a practical sense most things that we might move have a trivival amount of mass compared to the mass of the earth. Also things in orbit still have weight. It is just that the centrifugal force is equal to the acceleration of gravity....kind of like something floating.

 

[Hermit Scott]

http://en.wikipedia.org/wiki/Newton_(unit)

Hermit weight is a force. A newton is a unit of force. Mass is not a force it is a way to measure matter. More mass means more matter. Gravity is an acceleration and the amount of force depends upon the amount of mass being accelerated. Also remember the speed of acceleration in a vaccum is independent of the mass or density of the object. That is not perfectly true in that gravity depends upon both objects. But in a practical sense most things that we might move have a trivival amount of mass compared to the mass of the earth. Also things in orbit still have weight. It is just that the centrifugal force is equal to the acceleration of gravity....kind of like something floating.

I didn't want to be too knit pickey and go into the acceleration of centrifugal force, because some one invariably say it doesn't really exist. Yes gravity is given as an acceleration like like any change in momentum.
And yes I guess you could have 0 newtons making it not a force.
In a practical sense you can say something weighs X kgs, cause really we are all about the same distance from the center of the earth. I like engineering because engineers like to get close enough and chop off zeros when practical. Physicists and mathemiticians want to take pi to the last digit.
And BTW, I still believe the sun revolves around the earth. You just have to choose the center of the earth as the origin for your coordinate system.

 

[Maine Sail]

Doesn't it weigh the same as 100 tons of lead or 100 tons of feathers?

Out of the water yes, in the water no. Different substances, elements etc. have differing buoyancy in water so the net weight on the bottom of the ocean would be higher for lead than concrete of the same physical weight out of the water.

 

[Ross]

Like a 100 tons of cork?

 

[dscribner]

If you can't trailer it, it don't matter.