Gravity Vehicle C

[lmatkovic3]

Do you have any times and heights for the winners?

[_HenryHscioly_]

i heard that one school had really low 20s cm height but accurate..not sure if it was a medal
my 7th place was recorded at 29cm, 5.25s
I pracitced with two heights, 34 and 31, didnt have time to test other heights. I kinda eyeballed the height with a tape measurre on the side...so wasnt accurate(also how it was measured at competition..)

Troy's ramp was short, 35cm?
But they didnt medal
I still count w/e they did as a winner...their 2nd run, pencil somehow hit their car, or so I heard, so it was really off target.

[piimasta314]

i heard that one school had really low 20s cm height but accurate..not sure if it was a medal
my 7th place was recorded at 29cm, 5.25s
I pracitced with two heights, 34 and 31, didnt have time to test other heights. I kinda eyeballed the height with a tape measurre on the side...so wasnt accurate(also how it was measured at competition..)

Troy's ramp was short, 35cm?
But they didnt medal
I still count w/e they did as a winner...their 2nd run, pencil somehow hit their car, or so I heard, so it was really off target.

It depends on what the car is like, really. You just have to maximize your score. There's a point where the height of the ramp doesn't improve the speed enough to cancel out the points taken off for the height.

[Stingray355]

Actually it is the combination of the ramp and vehicle and will be different to some degree for every team. We call it the "crossover"point and you find it by making timed runs from different heights and calculating the scores. Once you find the optimized launch height for your combination going any lower or higher will simply reduce your score. For this part of the calibration we assume a particular distance from the target that is the same for all calculations so that we can isolate the variables we are measuring.

Obviously having a trigger that can be easily moved to different launch heights is preferred.Also the crossover will be different for different distances, that is to say the optimal launch height for your combination for a 10 meter distance will almost certainly be different for shorter distances. You can bracket to simplify the process.

[jacobxc]

Some bs happened at the Texas SO state yesterday. My partner and I got stupidly penalized for our paper clip. Our paperclip has been shoved into a block of wood to make sure the paperclip doesn't move out of place and mess up our data. So since it is in the block of wood it isn't technically on the "outermost part of the car". So now our car which got 6 cm away is in tier 2 and no longer in the runnings for first place.

[mrsteven]

I think that is actually a very fair call, you should read the rules very carefully to ensure everything going into your car is legal.

[iwonder]

I agree with MrSteven, it sounds like they were just enforcing the rules. I was there yesterday, actually, and I think they did a very good job with gravity vehicle, after the initial problem with impound and some confusion with a bad tape measure(it read that our ramp was 77cm becuase it didn't have a 0 mark). In the future I would suggest very careful study of the rules so this doesn't happen again.

Oh, and we don't know places yet, but if you're interested...
Target distance: 32mm
Time: 5.75
Predicted time: 4.4
Height: 30cm

[lmatkovic3]

That's a huge difference between predicted time and actual time...

[iwonder]

Yeah... I'm not quite sure why. I actually switched the predicted and actual by the way. Chances are that it had to do with the surface, we had to test on industrial carpet but the event was run on gym floors. We have really hard wheels so I'm not sure I'm buying it..

[jacobxc]

The issue was that after our 2 runs the the judge decided we had a construction violation, not during impound or at the beginning of our runs. Several other teams had a construction violation during impound, but were allowed to fix the issue, we were not. Those are the 2 grounds my team has, unfairness and the fact that it already passed impound. So if anyone thinks theirs is the outermost point of their car and surpass this vague rule tell me how you did it.