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See, nobody wants to answer that, so nobody's crazy enough (except me) to comment . . .

So far, to study for Metric I just estimate random things whenever I get the chance. Yesterday I had SO practice, so me and the girl who's on Metric got my science teacher's plastic orangutan and estimated the volume (in cc's) and weight. If you don't have a plastic orangutan, you can always use some other random thing (plastic gorilla? )

Yeah, but...how did you find the actual volume of your orangutan after estimating to see how you did? I doubt you submerged it in water ...

Density is not hard to measure. Measure the mass. Measure the volume. Divide mass by volume. Taa Daa. The unit for density is g/ml.

As you measure density ask yourself if you think your item would float in water. If so, expect a density less < 1. If not, expect your density to be > 1. You sort of know these things naturally. Apples and wood float. A marble and a coin sink.

Most solid or liquid things in the world will have a density rather close to 1, say between .1 and 10. A balloon full of air will have a much lower density, but assuming your item is not gas-filled you can sort of do a check and ask yourself.

All we're doing for practicing is to measure a few things every day. It's a skill to develop, like playing scales on your clarinet, I suppose.

Just accept that it's not likely for regional tournaments to ask difficult shapes, rather small cubes and such, pre-measured. I myself haven't been to a tournament yet, so I can't say this for certain

Fuzzy orangutans are hard to measure volume of, but non-fuzzy, non-squishy things can be measured like this:

Get the mass from a scale (duh)

Get the volume with:

1) Dunk it in water -- Eureka -- measure displaced water.
2) Memorize formulae (L X W X H)
3) Dunk in something waterlike -- such as rice.

That's not the issue I asked about much earlier, though. The issue is how could density be ran as a single 15-30sec (as suggested in the rules) station? It involves two measurements which may be a bit unrealistic to expect to be performed in that amount of time on the same object. Make sense?

It would be hard to measure density in a short amount of time and I am trusting that the supervisors will be sensitive to that and will allow longer.

Perhaps the rotation time is 30 seconds for estimate and 60 for measure. What could be done is a supervisor could devise two nearly-identical stations. So, teams 1,3,5, 7, and 9 will visit the station on this table that has an apple, a scale, and a container of water. The even number teams will visit a different station with an apple, scale, and a container of water. So, during estimating, they go rotate through on one station or another. Then during measuring time, the team visits the same station they went to earlier and get to stay through a bell-ring.

It can be done.

This is my first year doing this so I am totally stressed.

Basically all we have to do is memorize formulas right. Then try our best during estimation right.

Splicerblade wrote:This is my first year doing this so I am totally stressed.

Basically all we have to do is memorize formulas right. Then try our best during estimation right.

Well that is the bare minimum for competition but it's not a description of how to do well. Most important is to read the rules carefully, especially 3.b.iv. which says that in the measurement portion you need to estimate one digit past the resolution of the instrument you are using. For estimation, don't just "try your best"; prepare by practicing measurements of all of the properties listed in the rules, even temperature, volume, density, force, and come up with references for units you can compare in your head. Doing a lot of practice will separate you from the people who have a good guess and put you into the exclusive tier of people who have very little doubt or hesitation in their estimation.

This event bothers me for several reasons. It's not just the density thing. How about temperature? How can a supervisor hold something at constant temperature (scoring correctly requires this) for the duration of the event without an expensive temperature-regulated water bath normally found in a laboratory? I'm hesitant to asssume that even water won't have fluctuations in temperature over a few hours. It would equilibrate at room temperature (within what margin?), so I suppose an 'actual' temperature could be recorded before the event is ran or something (that's not good practice). Is that the best that can be done? That is a bit lame considering estimating room temperature is one of the simplest possible tasks.