Bottle Rocket B

[Whiteheat073]

Is bottle rocket performed indoors or outdoors? sorry weird question just curious

[Unome]

Is bottle rocket performed indoors or outdoors? sorry weird question just curious

Rockets can go 150+ feet in the air if they're good enough. I've so far never seen it run indoors.

[Fanglin]

Not true, my partner and i had the best times with 37%. Compared to a whole 1 second difference when the bottle was filled with 30%, 15%, or 45%(ect,)

As I said above, it does not make much of a difference. Percentage is not one of the things you should really work on. If you want to get the best times, make your rocket the lightest possible.

[logan aris]

im confused on the rules this year can you have a parachute on your bottle rocket if nothing comes off of the rocket

[A Person]

Yes, you can.

CORRECTION: You cannot. Misread the question, nothing can come off, you should use a backslider or something.

[andrewwski]

Not true, my partner and i had the best times with 37%. Compared to a whole 1 second difference when the bottle was filled with 30%, 15%, or 45%(ect,)

A 1 second difference could be caused by a number of different factors, of which water-to-air ratio is one, but winds, launch angle, and other external factors are others.

Well obviously the extremes won't work, but I was talking about 10% to maybe 40%. I have tested a ton of the combinations, and there is not much deviation.

Of course the behavior will be more extreme at the extremes, but it's still going to be nonlinear in that region, and while the impact will be smaller given a smaller region, it may be significant.

40% is 4 times more water than 10%...I think the effect is going to be noticeable. It may not be the largest contributing factor to shorter times, but seeing as it's easy to test, it's going to be worthwhile. My personal experience indicates that there is a noticeable difference between those amounts, but there can be other contributing factors that affect how much impact this has - e.g. size and shape of the nozzle, etc.

Mass will definitely impact the time greatly, and will also lessen the impact of the water-to-air ratio - a larger mass will be less sensitive to other parameters.

But it all comes down to what works best for you - the value of testing cannot be understated in events like these. But also recognize that there will be other contributing factors which makes it difficult to make assertions about general trends with a limited dataset. You can overcome this with more testing. Test several times with the same configuration and look at the spread in the data. Take enough measurements such that there is statistical significance to your observed trends.

[mso]

Hi All,

It looks like the only way carrying egg is loading it in the Nose Cone. From the Division 'B' rules 2016 it is mentioned that after safety inspection of the rocket,
eggs need to be selected and loaded in the rocket before launching. How the eggs can be loaded in the nose cone without re-attaching the nose cone to pressure
vessel, is that means violating the rules. If anyone has already designed/built the bottle rocket, highly appreciate if you can share the ideas.

Thanks

[JennFolsom]

First time for us to compete in Middle School Science Olympiad and meeting with our coach for the 1st time next week so lots of questions...

Competition parameters say no recovery system, but does that mean a parachute is excluded? I figure that a parachute is essential to this event and saw someone said you can, but hate to get DQed if not.

Anyone know?

On many of the example photos, more than just a single 2 liter bottle are used. Looks like a lot of long tube pieces, where do you buy those? Can I put anything additional on as long as not metal/sharp, etc.

Which type of 2 liter bottle brands do you like to use the most for this event?

Jenn

[SPP SciO]

In response to some comments above, parachutes and other recovery systems are not "banned" per se, but rules prohibiting any "change of shape" pretty much eliminate any parachutes, spinning blades, streamers, deployed wings etc - from the looks of previous competitions, backsliding is the way to go. Someone posted a great description of their backslider several posts back.

Note: I don't have the official rules in front of me now, but your team should when they're building. Last year, some of my students built a rocket from a big Smart-water bottle - ignoring the rule requiring the bottle be from a carbonated beverage. That was a pretty big one they missed, and there are other, smaller details to be aware of.

Has anyone had success with a glider-type rocket? We watched an interesting video where a bottle rocket resembling the space shuttle went into a perfect slow spiral descent. Seems like a neat idea, but is it easy to achieve stability? Internal gyroscopes are (hopefully) beyond the realm of division B...

[Fanglin]

Yes, you can.

actually, no you can't. You can't have any part of the rocket move while inflight.