Water Task

[aniSUKSatCHEM]

What does it mean by "closed container" in the rules? Can there be a small hole in the top of the container so that I can use a pipette to transfer water into the container?

[nicholasmaurer]

What does it mean by "closed container" in the rules? Can there be a small hole in the top of the container so that I can use a pipette to transfer water into the container?

Per the FAQ posted to soinc.org on 10/23/17: "The container must be closed but does not have to be air tight. When water is added to the container, any liquids and/or solids must stay within the closed container and no one can be physically exposed to them."

[Kyanite]

So the FAQS said you cant use salt water for the water task, would pouring the water into a container that has dry salt be against these rules? What do you all think?

[Unome]

So the FAQS said you cant use salt water for the water task, would pouring the water into a container that has dry salt be against these rules? What do you all think?

That seems to be legal to me. So long as the water being poured is not saltwater, it should be fine. However, you're probably better off doing something more reliable, like this:

So could we add water to a container that weighs it and presses a limit switch?

[ScottMaurer19]

So the FAQS said you cant use salt water for the water task, would pouring the water into a container that has dry salt be against these rules? What do you all think?

That seems to be legal to me. So long as the water being poured is not saltwater, it should be fine. However, you're probably better off doing something more reliable, like this:

So could we add water to a container that weighs it and presses a limit switch?

It is legal to pour the water into a container that has salt in it (according to the coaches clinic).

[andrew lorino]

So the FAQS said you cant use salt water for the water task, would pouring the water into a container that has dry salt be against these rules? What do you all think?

That seems to be legal to me. So long as the water being poured is not saltwater, it should be fine. However, you're probably better off doing something more reliable, like this:

So could we add water to a container that weighs it and presses a limit switch?

Couldn't the phrase "add water to a closed container so that it completes a circuit..." be seen as only allowing the water itself to close the circuit by using its own conductivity?

[ScottMaurer19]

So the FAQS said you cant use salt water for the water task, would pouring the water into a container that has dry salt be against these rules? What do you all think?

That seems to be legal to me. So long as the water being poured is not saltwater, it should be fine. However, you're probably better off doing something more reliable, like this:

So could we add water to a container that weighs it and presses a limit switch?

Couldn't the phrase "add water to a closed container so that it completes a circuit..." be seen as only allowing the water itself to close the circuit by using its own conductivity?

Yes BUT the way it is currently written (per coaches clinic) is that a circuit can be completed anyway. Not just through water's conductivity

[SluffAndRuff]

A little off topic but if a limit switch can be used, does a Lego NXT Touch Sensor fit the bill as well? I'm being a bit lazy for Invites and going the Lego route - does anyone know if a Touch Sensor works the same way (closes a circuit upon actuation)?

[Dark Sabre]

My personal take on the task description:
If I press a switch with my finger, my finger is not completing the circuit because my finger is not a conductor in the circuit. I am pressing a switch. The switch is completing the circuit.
If I touch between two high voltage lines, my finger is completing a circuit (to my detriment).

I think the spirit of the problem is clear to use water to "complete"/bridge an incomplete circuit.

Another way to phrase my perspective on the limit switch scenario: Is the water completing a circuit or tipping a (tiny) lever?

That said, the grape vine says that a weight approach is acceptable and I'm of course perfectly happy to follow FAQ answers whenever they appear.

If a limit switch to detect the weight of the water is acceptable, then I don't see any reason I wouldn't accept a wide variety of scenarios incorporating mechanical force. If the NXT touch sensor operates on a make/break basis, I'd lump it in with limit switches. If it uses something like a slide potentiometer to change resistance then it is not completing a circuit (only adjusting the resistance of it). I had RCX instead of NXT, so I don't know the answer off-hand. If the software only allows for on/off feedback from the sensor, I suspect it is probably a make/break device.

Keep in mind that the grape vine also indicates that an NXT microprocessor is an adjustable physical object and so can only be used on one assigned action (no FAQ on the topic as of yet). Which would make it a pretty expensive alternative to a limit switch

[nicholasmaurer]

The FAQ posted today seems to contradict (and therefore overrule) the guidance given at the coach's clinic. Since "it" in 4.b.iv is being defined as "the water" per the FAQ, the water itself must complete the circuit. This rules out using the weight of the container to trigger a switch.