Rules clarification

[windu34]

Ok let me clarify. I was not quoting the rules as I do not have them in front of me; I will let chalker do that. I could explain this to you in a technical way or I can make this clear and the way most everyone correctly interprets the rules: the mass can only be dropped once. This is not at all a concise and scripted statement of the rules, but as I would rather not get technical, this is (essentially) the conclusion you will receive from pretty much anyone
Please try not to twist the wording of the rules (and my statements) into ridiculous extremities

[chalker]

I AM trying to ask someone impartial for an answer. I DO know how to read and I've read the rules many times. If you see something in the written rules that states - clearly - that what I suggested cannot be done - that is fine with me. I just want to know before having the kids start on something. I do not see what you are referring to. Please lead me to, or post a citation from, any written rules that state things the way you just did. Again, I am not trying to argue. Just seeking clarification now before any of the kids start something. If this is about science and using the scientific method - the rules need to be clearly written - or at least - fully explainable by some sort of authority. Thus the reason I am asking here on this forum. You state . . . "Students may not touch the device at all except via the release mechanism which may not impart any significant energy into the device." That makes NO sense to me at all. You say the student cannot take any action before releasing the trigger, and you also say releasing the trigger "may not impart any significant energy into the device." Going by that - there cannot be any power from anywhere, as I read it. Part of this is to harness Newtonian gravitational energy and convert it to air flow or air pressure - correct? At some point in time, either before the release trigger is tripped, or at the time it is tripped - a weight along with gravity has it's energy harnessed. The way I read what you wrote - there is no allowance anywhere for this aspect of the procedure. If, let's say that one pull of a string permits a weight to fall, that compresses air, and fires a projectile - it is not allowed by what you just stated. That because activating that trigger is "imparting significant energy."

First off, welcome to Science Olympiad! We really appreciate you being involved and asking detailed questions to better understand everything. SO is 99% driven by volunteers, parents and coaches, that all have a desire to be engaged in STEM education. Unfortunately, you'll also find that like any large organization, we have our own quirks, lingo, and shortcomings. Sorry about that and please don't be discouraged if someone comes off a little harsh or something doesn't seem to make sense.

To re-iterate my previous statement, this is not the place for official clarifications or statements. However as the Chair of the SO Physics Committee (and the creator of the Air Trajectory rules in particular), I try to utilize this forum the best I can to help out those involved in SO that have questions or concerns. In general, we try to design the rules so they impart a multi-faceted challenge that makes it easy for teams just starting up to be involved, yet still makes it possible to differentiate the 'elite' teams that regularly compete at the National tournament. Safety concerns also weigh heavily in our process.

Events like Trajectory have been around since the very beginning of SO (all the way back in 1984). We're constantly tweaking the rules to make them better and present new challenges to the competitors (while keeping the general spirit of an event the same from year to year). So, regarding your idea to repeatedly re-raise the weight, it's so far 'outside the norm' that most people who've been regularly involved in SO would automatically dismiss it out of hand as against the spirit of the problem. But that's exactly the kind of creative thinking we strive to encourage in SO! While it's not explicitly prohibited in the rules (note space constraints prevent us from addressing all possible scenarios in the rules), I think there are several specific rules that would indeed make it a prohibited technique (or at least virtually impossible to engineer):

3.a. states all launch energy must come from the gravitational potential energy from a falling mass (which obviously comes from the competitors at some point). Read strictly, it's a single instance of a 'falling mass', not a falling mass, followed by another instance of a falling mass (due to the mass being raised up again), etc. etc.

3.c. states all air chambers must start at and return automatically to ambient air pressure. If the students are repeatedly lifting a mass and power an air pump, I can't imagine how you'd ensure the air chambers return automatically to ambient air pressure. If the students just walked away in the middle, there would be air pressure built up in the tank with no outlet. Note 2.d. allows for a DQ for unsafe operation.

3.e. states that ONLY the triggering device can extend outside the launch area and keep the students 75cm away from it. Activating it must not contribute significant energy to the launch (the wording says contribute, not impart, which should address you concern at the end of your post). 4.b. says students can only touch the triggering device during a launch. Thus to implement your idea, students would either need to get within 75cm of the device (a penalty per 5.b.) or repeatedly pull on the triggering device (which would contribute energy to the launch).

Note that that rule also refers to triggering device in the singular, not plural. That effectively prohibits the use of multiple triggering devices to handle different stages of a launch.

4.c. requires the device to be within the launch area before and after the launch, and automatically return to the launch area immediately after launch. Thus that makes it virtually impossible for the competitors to interact with some other portion of the device during the launch.

Note that we've sized the mass, projectiles, and target distances appropriately such that for most teams it's not a problem to get enough energy from the falling mass to launch the projectile the max distance.

Hope this helps!

[jdemaris]

Thank you for the well thought out and written reply. All appears clear to me now in reference to what I already asked.

One new question. This in reference to 3 a. in the rules. Division B is allowed a falling mass less or equal to 11 lbs. (5 kgs). I assume mechanical advantage can be used -perhaps with a fulcrum -so that the falling mass can be on the end of a sort of see-saw. Let's say such a weight is placed on one side of a fulcrum and has a 2 to 1 advantage. That means the force on the other end would be twice what the falling mass creates via Newtonian gravity (more-or-less). If I am interpreting the rules correctly - all that counts here is the actual weight of the falling mass on the side of the fulcrum that drops. I.e. the discrete weight itself and also the weight of the fulcrum arm on the side that drops. Am I correct that it is allowed to increase the force created by the dropping weight along as that weight does not exceed the 11 lb. limit?

[chalker]

Thank you for the well thought out and written reply. All appears clear to me now in reference to what I already asked.

One new question. This in reference to 3 a. in the rules. Division B is allowed a falling mass less or equal to 11 lbs. (5 kgs). I assume mechanical advantage can be used -perhaps with a fulcrum -so that the falling mass can be on the end of a sort of see-saw. Let's say such a weight is placed on one side of a fulcrum and has a 2 to 1 advantage. That means the force on the other end would be twice what the falling mass creates via Newtonian gravity (more-or-less). If I am interpreting the rules correctly - all that counts here is the actual weight of the falling mass on the side of the fulcrum that drops. I.e. the discrete weight itself and also the weight of the fulcrum arm on the side that drops. Am I correct that it is allowed to increase the force created by the dropping weight along as that weight does not exceed the 11 lb. limit?

Correct. Although keep in mind that depending on the exact design, part of the arm that connects the mass to the fulcrum could be considered part of the mass too and would need to be weighed.

[jdemaris]

Thanks. I kind of figured the weight the arm would count as part of the weight mass. But to be technical -the weight of the arm on the other side that goes up would then probably have to be subtracted since it is fighting against gravity ?? A minor point and I doubt we'll be getting into anything with specs so close it will matter.

[SPP SciO]

Thanks. I kind of figured the weight the arm would count as part of the weight mass. But to be technical -the weight of the arm on the other side that goes up would then probably have to be subtracted since it is fighting against gravity ?? A minor point and I doubt we'll be getting into anything with specs so close it will matter.

For what it's worth from one new coach to another - going with something simple, like the weight/soda bottle/PVC ping pong launcher that's tried and true is the best way to start. The bulk of the fun - and learning - comes during the testing, not poring over the rules and fiddling with a complicated machine (leave that for the Mission Possible team). The more they launch, the more ideas they will have for improvement, and they can do some real engineering. Good luck - air trajectory is a fun and very visible event, let your whole school get in on the fun and you'll wind up with a great device.

[DoctaDave]

Will there be 2 different bucket shots (1 for hitting within 500mm of each target) or just one bucket shot? If there is only 1 bucket and you hit within 500mm for both targets do you get 2 tries to hit the bucket?

Also do any of you think there is an issue with using a laser as long as it is removed before each shot? Technically it could be defined as a tool and not part of the device since it is not present during the shot but I would like to know others' opinions.

[bernard]

Will there be 2 different bucket shots (1 for hitting within 500mm of each target) or just one bucket shot? If there is only 1 bucket and you hit within 500mm for both targets do you get 2 tries to hit the bucket?

Also do any of you think there is an issue with using a laser as long as it is removed before each shot? Technically it could be defined as a tool and not part of the device since it is not present during the shot but I would like to know others' opinions.

You can get up to two bucket shots. The bucket shot replaces the second shot at a target if the first one is within 500 mm. So you could do close-bucket-far-bucket or close-far-bucket bucket, etc. but not close-bucket-bucket-far, etc. If your first shot is within 500 mm, you could also instead choose to attempt the same target again, giving up your chance at a bucket shot. You get to pick the order of your shots, but before you get any bucket shots you'd have to qualify yourself for it. If I remember correctly, the winning students in Division C last year at Nationals had two bucket shots (http://www.scioly.org/phpBB3/viewtopic. ... 55#p275795).

Last year an FAQ was published (doesn't necessarily apply to this season) that stated lasers had to be removed before launches but were allowed. The rule regarding electrical components seems not to have changed so as a supervisor I would allow it.

[DoctaDave]

So are there two separate bucket shots of different distances or is there one unique bucket shot but with two possible attempts?

[windu34]

So are thereor is there one unique bucket shot but with two possible attempts?

Assuming you qualify, two separate bucket shots of different distances