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View Full Version : Weight: amt of matter in object is weight. True or false


andr3a1435
Nov 29, 2007, 04:19 PM
Is the answer false because that is mass

red_cartoon
Nov 30, 2007, 09:48 AM
False

Mass is the amount of matter present in object. Weight is the force exerted on that object due to gravitational pull.

mum45
May 1, 2009, 12:23 AM
You had me at mass, and lost me at weight. All I could think about was a box of feathers would be a lot lighter than the same size box of rocks!

Capuchin
May 1, 2009, 02:09 AM
You had me at mass, and lost me at weight. All I could think about was a box of feathers would be a lot lighter than the same size box of rocks!

In a gravitational field this is true, but in zero gravity they would weigh the same (0N), but the rocks would still have more mass.

Mass is the amount of stuff, weight is the amount of force needed to lift it, and is dependent on the gravitational field.

Perito
May 1, 2009, 04:43 AM
All I could think about was a box of feathers would be a lot lighter than the same size box of rocks!


Don't confuse density (mass/volume) with weight or mass. The old kids' question, "which weighs more, a ton of feathers or a ton of lead?" comes to mind.

As started above, mass is a property of the material. If you were in zero gravity, any mass would have zero weight. On the moon where gravity is less, you would weigh less than you do on earth -- but you'd have the same mass.

We normally use weight to determine mass -- at least here on earth. However, in very accurate experiments, we have to correct for small changes in the force of gravity (gravity is less at higher altitudes, for example) and for the buoyancy of the material in air. The buoyancy requires a knowledge of the volume of the object.

mum45
May 1, 2009, 07:53 AM
:eek:
Are y'all trying to teach me?? :eek:

Capuchin
May 1, 2009, 09:35 AM
:eek:
Are y'all trying to teach me???:eek:

That's pretty much why we hang aroun dhere ;D

mum45
May 3, 2009, 10:49 PM
Mmmhmmm. Buoyancy of material in the air? Ohboy, y'all ARE going to teach me. :p see I just was all thinking "oh, yeah, rocks are really light in the water, I get it", then you start talking about buoyancy of material in the AIR!! :confused::confused:
Gets out the FAFSA.. Going back to school in the fall. Dern it all.:eek::eek:

Unknown008
May 4, 2009, 06:34 AM
LOL mum45... if you come here, especially in the science threads, you sure will see yourself in school! :p