what is the difference between mass and weight?
103036
We often use the terms "mass" and "weight" interchangeably in our daily speech, but to an astronomer or a physicist they are completely different things. The mass of a body is a measure of how much matter it contains. An object with mass has a quality called inertia. If you shake an object like a stone in your hand, you would notice that it takes a push to get it moving, and another push to stop it again. If the stone is at rest, it wants to remain at rest. Once you've got it moving, it wants to stay moving. This quality or "sluggishness" of matter is its inertia. Mass is a measure of how much inertia an object displays. \n\nWeight is an entirely different thing. Every object in the universe with mass attracts every other object with mass. The amount of attraction depends on the size of the masses and how far apart they are. For everyday-sized objects, this gravitational pull is vanishingly small, but the pull between a very large object, like the Earth, and another object, like you, can be easily measured. How? All you have to do is stand on a scale! Scales measure the force of attraction between you and the Earth. This force of attraction between you and the Earth (or any other planet) is called your weight. \n\nhttp://www.exploratorium.edu/ronh/weight/
32418
1 inch ~ 2.54 cm\n1 ft ~ 30.48 cm\n\ntechnically, a pound (lb) and grams/kilograms do not measure the same thing. a pound is a measure of weight (a force) while a gram is a measure of mass.  At sea level on earth, where gravity is about 9.81 m/s^2, a mass of 1 kg would approximately have 2.2 lb of weight.  But for basic science classes, this is assumed to be interchangeable
31946
reverie's wrong.  Most mass actually comes from kinetic energy, not rest mass.  you can correcly give energy (including heat energy) the same units as mass so it makes sense to say "one pound of heat"... but force is something different entirely.
145057
..also they're measured in different units.\nVolume is measured in cubic units (m^3, ft^3 etc), whereas  weight is measured in units of Force (Newtons, or foot pounds)\n\nYour volume is fixed (unless you have a large dinner) whereas your weight varies depending on your altitude. You actually weight less at the top of Everest than you do at sea level.\n\nIt should also be noted that weight and mass are different.
69858
Weight is a force.  The National Institute of Science and Technologiy defines it here as such.\nhttp://physics.nist.gov/Pubs/SP811/sec08.html\n\nA force is acceleration times mass.  Weight is the accleration due to gravity times mass.  On the Earth's surface, this is approximately:\n\nWeight = Mass x 9.8 meters/second^2\n\nFor a accurate conversion, you would need to use the acceleration due gravity minus the accelration due to centrifugal force at your exact location.  \n\nThis is why physicists more commonly use mass than weight to describe an object.
508636
same mass, same weight
344825
density is mass divided by volume - so if you know the volume and the density, then you multiply them to get the mass  (which is synonomous with weight)
881632
Mass of an object never changes unless it is changed physically.\nMass has something to do with matter.  Weight will change, which is first decided by the amount of gravity.
42452
Tell them that the mass is the actual ammount of stuff(matter) in a given object.  Weight is the force of gravity pulling on the stuff (mass or object).  The gravity is caused by the ammount of mass in the other object.  So on earth it has a constant mass so the ammount gravity on an object is constant.  Therefore on earth we can measure the mass of an object using its weight.
994962
Mass is kind of like the object's inherent inertia.  The inertia it would have regardless of its location and even if it were standing still.\n\nAn object's inertia is it's resistance to change.  Different things besides mass can affect an object's inertia.  For example, it's position can affect inertia, especially when talking about rotational motion.  An object located at a 1 meter wheel's rim has more inertia than an object located at the wheel's hub (lots more, in fact, since moment of inertia is equal to mass times the square of it's distance from the rotational axis).
691415
The SI (metric) unit used to measure mass is the gram.\n\nThe Imperial (English) unit used to measure mass is pounds and ounces.
406606
Your question is very awkwardly worded. I assume you're talking about mass, not weight. Mass is the amount of matter in something. Weight is force that gravity "pulls" on it. With the same object, mass is always constant. Weight changes if you're on the moon, or in outer space.\n\nAs for its gravity, do you mean the Earth's pull on it, or the gravity field the object projects? If it's the former, then yes. That's how weight is defined. All things fall at the same rate, however. As for the latter, then, yes, the mass of an object dictates how big the gravity field around it is. The Sun projects a huge gravitational well, while a penny projects next to nothing.
17651
I assume here you're asking about the Earth's mass (mass and weight are different concepts and often confused).  The earth's mass is 5.9736 x 10^24 kg.
26504
The mass is a property of an object, a fundamental measure of the amount of matter in the object. The usual symbol for mass is m and its SI unit is the kilogram.\n\nThe weight of an object is the force of gravity on the object and may be defined as the mass times the acceleration of gravity, w = mg. Since the weight is a force, its SI unit is the newton.
1134237
On earth, mass and weight are equivalent, but in physics, it's more correct to use mass (since sometimes objects in physics problems are not on earth!)\n\nSo if the object weighs 1 kg, you can use 1 kg as its mass. One newton is the force needed to accelerate 1 kg (mass) at a rate of 1 meter per second^2.
632240
Both mean the same in a broad sense but there is a difference. Scales are machines which are used in shops like grocery. They are used to weigh the items purchased where as a weighing machine is used to weigh people like the weighing machine you have in your house.
975657
Most American countries use scales to measure an object's weight, or Earth's gravitational pull on it, while most European countries use balances to measure its mass- a measure of the amount of matter in the object. The reason for European countries to measure mass instead of weight is because mass is a more reliable way to measure things, because it doesn't change in relation to your position on Earth.