Mission Possible C

[Balsa Man]

#1 In 4a, since we bring our own items, do we bring all 30 and the event supervisor picks which ones we will use, or is it up to us?

#2 I assume the rules mean, 1-10 golf tees, 1-10 paperclips and 1-10 marbles, NOT 1-10 tees, and 10 paperclips and 10 marbles, correct?

I was not making the connection to rule 5e: 5 pts awarded for each object successfully sorted in its correct final container (max=150 pts.). So we must have 1 golf tee, 1 paperclip and 1 marble to "start" the event, but we can have more to get more points in sorting.

FAQ is saying that at a minimum 2 items, 1 each of the of the three listed. For the sorting scoring bonus, 5 points per object (max 150), so 2 would score 10 points. To get the max of 150, you will need 30 objects; 10 of each.

If you make your own golf tees, are they unmodified?

Purely personal opinion- since the rules are silent on allowable manufacturers of objects, there's nothing prohibiting you making them. Making, per se, is not modifying. If what you make looks/feels/is like commercially available, I don't see any basis for dis-allowing them. If, however, there's something in the size, material, shape that is different from commercial, and that makes the sorting easier, or that makes it work, I could see an ES dis-allowing by either invoking the 'unmodified' rule (saying you've modified the design of a tee), or invoking spirit of the rules- unfair advantage because you've made something that gives you an unfair (sorting) advantage, that is different from the obvious intent of the rules- that the objects be or be exactly like commercially available.....

[Robotica]

I'm confused about what components we can use, photocells are allowed, but into order to use a photocell wouln't I need a transistor, resistor, etc. to make it switch something?

Rob

[EmeraldChocolate]

The rules are so confusing this year
First of all, do we provide the materials for the starting task? And will we be able to decide where to pour it into in our device? (I assume so, since haphazardly pouring in these items would risk breaking things and not setting off the next action). Also, from reading through this forum, I just want to clarify. If we used mechanical, such as a fan, to push another mechanical, as in a ball down a ramp, is this two mechanicals? or just one?

[chalker]

I'm confused about what components we can use, photocells are allowed, but into order to use a photocell wouln't I need a transistor, resistor, etc. to make it switch something?

Rob

There is a clarification that should help clear up your confusion: http://www.soinc.org/official_rules_clarif

[Cougars]

The rules are so confusing this year
First of all, do we provide the materials for the starting task? And will we be able to decide where to pour it into in our device? (I assume so, since haphazardly pouring in these items would risk breaking things and not setting off the next action). Also, from reading through this forum, I just want to clarify. If we used mechanical, such as a fan, to push another mechanical, as in a ball down a ramp, is this two mechanicals? or just one?

Check the FAQ on national site for sure, but yes teams bring their start items and must pour a minimum of two different ones in to start the system. Yes you pour them into the place you want, which starts the system.

[Flavorflav]

Maybe the blackbox question is already spelled out in the rules, to some extent at least. Check rule 3g. You can't see the chemical reaction inside a battery, although you'll probably see the result of the flow of electrons just fine. To me, this means that when you trigger a switch to close a circuit, it is mechanical to electrical only. Lighting a match is visible. So if you energize a nichrome wire which lights a match, it should be Electrical to Thermal to Chemical and then to Thermal or EM, depending on what you do with the lit match.

I have been struggling with the distinction between examples like this of the match and that of the battery, and I have come up with another one that works for me. With a battery, the chemical reaction that causes the potential difference between the two terminals occurred long before you threw the switch, so all your action does is allow electrons to flow. With the match, the thermal energy in the nichrome initiates the chemical reaction in the match, which then releases the thermal and EM energy.

[olympiaddict]

Sorry, but I don't think that's true.

The anode and cathode need to be connected in order for electrons to flow, which is what allows a chemical reaction to take place.
That's why batteries don't discharge when not connected to a circuit powering something (simplified view but the point is still relevant).

Not the best source ever but says it pretty explicitly:
http://www.energyquest.ca.gov/story/chapter05.html

[Flavorflav]

From your link: "When zinc is inserted into an acid, the acid begins to eat away at the zinc, releasing hydrogen gas and heat energy. The acid molecules break up into its components: usually hydrogen and other atoms. The process releases electrons." The reaction at the cathode may require electrons, but flipping the switch did not begin the process at the anode. To put it another way, if there were not a pre-existing potential difference, then there would be no electron flow.

[ryang353]

Do the one pint pint containers have to be unmodified? Also can other items to assist in sorting, such as magnets, be inside the pint containers?

[gorf250]

From your link: "When zinc is inserted into an acid, the acid begins to eat away at the zinc, releasing hydrogen gas and heat energy. The acid molecules break up into its components: usually hydrogen and other atoms. The process releases electrons." The reaction at the cathode may require electrons, but flipping the switch did not begin the process at the anode. To put it another way, if there were not a pre-existing potential difference, then there would be no electron flow.

If a battery had a pre-existing potential difference, ie. a surplus of electrons, why would that not discharge immediately into any metal objects/ground? Furthermore, why would they even bother putting chemicals into batteries if they didn't provide current only when a load was attached? Why would they not just create a component with two charged electrodes? If the reaction started immediately, then as soon as you assembled a battery, would the chemicals react entirely and become inert? I think this is pretty clear: " Electrons flow from the battery into a wire, and must travel from the negative to the positive terminal for the chemical reaction to take place. That is why a battery can sit on a shelf for a year and still have plenty of power — unless electrons are flowing from the negative to the positive terminal, the chemical reaction does not take place. Once you connect a wire, the reaction starts. The ability to harness this sort of reaction started with the voltaic pile"
From http://www.chromebattery.com/battery-ki ... eries-work