Weight is a measure of the quantity of matter?

Question

true or false

Answer 1

False - That's mass. Weight is the force of gravity on an object.

Answer 2

Bad question...because the answer is, it depends.

Weight is just the force of gravity W = mg = GmM/R^2; where m is mass (matter) of the weighed object, g is acceleration due to gravity, G is a constant, M is the attracting mass (e.g., Earth), and R is the distance between the centers of the two masses. From the above, we see that g = GM/R^2; so the gravitational acceleration varies according to R and M.

Now as to why the answer is, "it depends." We see that one can write m = W/g; so that if we know g and weigh the object, we can find its mass (matter). So if we are willing to accept weight as an indirect or surrogate measure of mass, then the answer is true. That is, we can always derive mass if we measure both the g and W factors.

On the other hand, if the question means is weight a direct measure of mass, then the answer is false. Why? Because we also need to know what g = GM/R^2 is. And that varies from place to place.

That is, we cannot simply assume g = 9.81 m/sec^2, which is kind of the average g on Earth's surface R distance from the center of Earth. But what if we're weighing an object on the surface at r of the Moon of mass m where m < M and r < R? Clearly g on the Moon will be way less than that on the Earth.

Thus, the bottom line is...it depends. It depends on if we know or do not know what g is.

[We can find a mass m if we know a mass M and balance them on a teeter totter like device. In which case we have f X L = F X l and mg X L = Mg X l; so that m = (l/L)M and, ta da, the g's cancel out. L and l are the distance each mass is sitting from the pivot point of the teeter totter. But here, again, weight is not the measure.]

Answer 3

Weight is not defined as the quantity of matter, but you are not incorrect by calling it a measure of the quantity of matter that something contains.
For example, I weigh less than a sumo wrestler, hence I would use that difference in weight to assume that the sumo wrestler contained more matter than I.

It is however incorrect to simply say weight OR mass is the quantity of matter that an object contains. This is simply not an accurate definition of matter after looking into Einsteins theory of relativity.
It is well known that mass increases when you reach speeds comparable to that of the speed of light, and we know that the amount of matter that an object contains is constant. (disregard mass - energy conversion at high energies)
It is for that reason that we define mass as the measure of the inertia of an object. Its resistance to a change to its current velocity, whether in motion or at rest.
This is the accepted definition of mass.

Force is equal to an objects mass multiplied by the acceleration that it undergoes.
Weight is a force, with the acceleration being the acceleration due to gravity which is (9.81 m/s2 approx near the earths surface)

Answer 4

Weight is a measure of force (F=mass x acceleration), thus without knowing the acceleration, one cannot deduce the mass. It is therefore only an indirect measure of the quantity of matter. Mass is the measure of the quantity of matter.

Hence, the answer is false, because weight is a measure of force.

Answer 5

false, weight is the force with which a object is pulled toward the surface of earth.

weight changes at diferent heights, and even in poles and equator.

but the measure of quantity is mass, SI unit KG

it never changes for the same quantity, any where in universe.

Answer 6

false...mass is a measurement of the amount of matter something contains, while weight is the measurement of the pull of gravity on an object.
a lot of times people use the words interchangeably but if you want to get nitty gritty they mean different things. Like in chem lab if your measuring out a certain amount of crystals, you're massing them, not weighing them.

Answer 7

True.

But its not an invariant measure - it depends on gravity.

Rest frame mass is an invariant measure of the quantity of matter.

Those who say false clearly do NOT understand physics. While weight is a force this force is proportional to the quantity of matter and hence IS a measure of it.

Answer 8

false, it is force that pulls the object towards the surface of the earth, mass is the measure of any matter

Answer 9

It's mass, generally in kg.

Answer 10

No, mass is