Estimating 1 lb?

[fireballs619]

Ok, I know that this isn't truely space math, but I figured if anyone were to know, it'd be those on orbiter-forum. Is there any accurate way to estimate if an object is one pound, without using a scale or water displacement?

 

[tori]

You mean like eyeballing it, or feeling it (experience based estimates)?

Or in microgravity?

 

[fireballs619]

You can both eyeball and feel it, just no measurements of any sort. Its for a contest.

 

[tori]

Well, then just get a feel for it, grab and weigh a bunch of different things and build up your experience

 

[Notebook]

Any rules in this contest? Do you know the likely objects?

N.

 

[martins]

You could eat it, and then test how long it keeps you going on a cycling machine. As long you know what you've eaten, and its usable energy content per weight, you can work out the weight.

This of course only works if the usable energy content is > 0. Also it doesn't work well with poisonous substances, because you may drop off the bicycle before the end of the experiment.

 

[Urwumpe]

Take a sphere, and let it drop from a high building, and then calculate the terminal velocity. a sphere has a known drag factor, and the terminal velocity is only a function of object density and air density.

 

[fireballs619]

Any rules in this contest? Do you know the likely objects?

N.

Well, the contest is as follows;
You are given a large quantity of small objects (I'm guessing it will be some sort of candy, or similarly sized object) and must set aside how much you think is a pound. If you win you get to keep it.

I don't care so much about winning, it just got me thinking as to if there is an accurate way to estimate weight.

 

[kwan3217]

Back in high school chemistry, we were handed a kilogram mass for a scale, a black hollow metal cylinder filled with the right amount of lead shot. We each held and hefted it, then passed it along to the next student. I still base my idea of a kilogram on that.

For a pound, imagine a coffee cup filled with water (or coffee, I guess). A cup of water weighs about 8 ounces, and the cup itself weighs about 8 more ounces or so.

Plastic soda bottles don't weigh that much more than their contents, so if you imagine a 20-ounce soda, it's a little less than that. If you imagine a 2-liter bottle, its about one quarter of that.

Or if you know what kind of candy it is, buy a bag of it yourself and weigh out the appropriate number of them.

 

[tblaxland]

Some creative ideas here. Like the saying "Practice makes perfect", I worked for sometime dispatching packages of electrical goods by mail and we had to weigh them to determine the postage. We used to have bets to see who could estimate the weight before putting them on the scales. You get pretty good after a while and I found not looking at the package helpful because your eyes play tricks on your perception of the weight for varying densities. The packages were typically in the range 0.2 to 2.0 kg. Good luck!

You could eat it, and then test how long it keeps you going on a cycling machine. As long you know what you've eaten, and its usable energy content per weight, you can work out the weight.

:lol: Nice backyard calorimeter, and especially useful for candy. For an equally accurate experiment, you could estimate the mass by measuring gravitational microlensing

 

[Andy44]

Well, if you can't make any measurements at all, then there's no way to tell, since feeling the force feedback with your hand or watching how much it deflects the surface it rests on with your eyes is a type of measurement...

But if you can use your eyes, you could attach a model rocket motor of known total impulse (thrust times duration) and see how it accelerates the mass.

This is "Orbiter" Forum after all, we do everything with rockets around here. Nuclear rockets if we can get away with it.

 

[Juanelm]

Well, the contest is as follows;
You are given a large quantity of small objects (I'm guessing it will be some sort of candy, or similarly sized object) and must set aside how much you think is a pound. If you win you get to keep it.

I don't care so much about winning, it just got me thinking as to if there is an accurate way to estimate weight.

The rules don't say anything about scales then? Can you use any type of instrument or tool? If not, its more like a guessing game.