Trajectory B/C

[sean9keenan]

I don't understand what to do for the four graphs. I have one graph (independent variable: launch angle, dependent variable: distance traveled), but what variables would be used in the other 3 graphs? There isn't a time component or anything like that...

Some devices have different power settings available, or you can change the type of elastic you used, data groupings from one setting I bet would be acceptable as well (to show how accurate your device is, not sure if this would be allowed). Or... and I don't terribly recommend this, but you could make educated guesses as to what the data would look like with a different elastic, or by tightening your current elastic... I'm not entirely sure what a judge would do in this case, it'd be very hard for them to prove that your data wasn't actually real, but I'd only suggest this if you didn't have much time left.

[zyzzyva980]

Our graphs are made up of the distances: Since we're in division B, we make graphs for each distance 2-6 m and make the independent variable the elevation and the dependent variable the launch angle. We also have one for each target at floor level from 2-8 m.

[AlphaTauri]

Yeah, our trajectory team from last year ended up with about 10 pages worth of graphs and data. Some of that was because of the sheer amount of different settings we can use on our catapult, but we had like 3 graphs just for distance (floor-level) and a whole lot for elevations. Especially with the bucket shot this year, you could find the settings for different distances, different left/right location, and different size buckets.

Speaking of the bucket shot, would it be easier to collect info like "4 meters out, 1.5 meters left/right" or use the Pythagorean Theorem and say "4.3 meters distance" for the very same shot?

[zyzzyva980]

Probably. What my team does is take a tape measure and measure out to the optimum point to hit the bucket (without touching it, of course) and insert that distance into our equation. Remember, the distances are not always accurate.

[anon y mouse]

I would assume that measuring the actual distance the bucket is away would be more useful, but you may want to keep in mind how quickly you can accurately aim your device while still firing all shots within the time limit.

[sj]

Actually, assuming the bucket is indeed precisely where it is said to be then using the pythagorean theorem would be more accurate and faster

[zyzzyva980]

I disagree, it would be faster to measure straight to the bucket with a tape measure. One person holds one end, the other goes over to the bucket and you get the exact measurement. Plus, you get to measure to the point in the bucket where it's easiest for the ball to stay in. There are certain points that the ball bounces out and some where it stays in. It is also more accurate this way, because the bucket is almost never exactly on the right spot.

[andrewwski]

It would definitely be faster to punch it in a calculator...

If the bucket isn't on the right spot, it's a poorly run event.

[zyzzyva980]

Yes, to punch it into a calculator would be faster, but I feel that for the most accurate measurement you would want to measure to the point in the bucket you want to hit because 1) That way it actually gets to the point you want to get it to, instead of the center, where with smaller buckets it's practically guaranteed to bounce out and B) In the case that the bucket is off a few centimeters one way or another, which is definitely possible, you won't miss because they gave you the wrong number. It's hard to place the targets exactly right on; we always measure everything to be on the safe side. Yes, it takes up time, but eight minutes is a long time, and accuracy is much important than speed.

[starpug]

Yes, to punch it into a calculator would be faster, but I feel that for the most accurate measurement you would want to measure to the point in the bucket you want to hit because 1) That way it actually gets to the point you want to get it to, instead of the center, where with smaller buckets it's practically guaranteed to bounce out and B) In the case that the bucket is off a few centimeters one way or another, which is definitely possible, you won't miss because they gave you the wrong number. It's hard to place the targets exactly right on; we always measure everything to be on the safe side. Yes, it takes up time, but eight minutes is a long time, and accuracy is much important than speed.

Well if they place it a few centimeters off, you may still get it in the bucket since the bucket's radius is probably bigger then any measuring area they are going to make.