Mass is a property of the object. Weight is the force that the mass exerts.

I think you can only derive the mass indirectly. By finding out it's weight and then backing out the gravity multiplier for the particular planet on which you're doing the measurement.

Mass, a scalar quantity, is measured on a beam balance. Standardised weights on1 side and the "mass" on the other. You have weight, a vector quantity, sussed closely enough. The simple way to measure it is to suspend the "weight" on a calibrated spring with a scale next to it. In other words you're measuring the effect of gravity on that "weight". With a beam balance gravity acts equally on both sides of the beam, therefore mass is unaffected by a change in gravity.

Weight is actually the force exerted by a mass due to gravity, and so it is measured in Newtons. However, for convenience and by convention, scales are then calibrated to read the mass equivalent in kg. You will remember that F=ma, so for a 1kg mass, m=1 and a = 9.8, so F = 1x9.8 = 9.8 newtons. But, instead of writing 9.8N on the dial of your bathroom scales, they write 1kg.

Some scientific scales will show readings in Newtons, but who wants that in their bathroom?

yes, all of the above. Mass is defined by the carbon 12 atom these days. Or it was 30 years ago. But carbon is bad. Aw sheet, back to re-education camp for me

my grandma used to go to mass on sunday

I wonder if they selling Gold as n mass or weight?
The same ounce could be as much as 6 times cheaper on the Moon, slightly more on Mars but will be quite a precious when sold on Jupiter

See this is the problem with the Internet... Too many people confusing their opinions with facts.

theDoctor said..
my grandma used to go to mass on sunday

No, that was mas.

Harrow said...
You will remember that F=ma, so for a 1kg mass, m=1 and a = 9.8, so F = 1x9.8 = 9.8 newtons. But, instead of writing 9.8N on the dial of your bathroom scales, they write 1kg.

a being acceleration, which we are all constantly doing right now at about 9.8m/second, which I think is pretty trippy.
The 9.8 is, I guess, a constant here on Earth so is just removed from the equation (I didn't really attend high school).

...so you could arbitrage by buying in one location and selling in another.

Interesting exercise
You have a 0.5% difference between the equator and the poles just from centrifugal force, you weigh less at the equator.
Then you lose another 0.3% for every 9,000m of altitude.

So where is the highest location near the equator, and the lowest place nearest a pole, where we can trade gold?

Of course trade costs and transportation are going to kill us.

It's not that far fetched. There are trading companies that setup in locations between major (stock) trading hubs to take advantage of the speed of light. Serious auto trading software wars: www.wired.com/2012/08/ff_wallstreet_trading/

Because of you granny knot, fool!

cisco said..

Pink shirt...acid wash denim pants...comb-over with Chuck Norris beard & combo of pocket pen & hip pouch - that teacher's got cool written all over him!