Gravity Vehicle C

[joeyjoejoe]

So to make sure I understand your take on this:
When the car is in launch position, all wheels must touch the ramp.
Prior to launch, we can adjust height and position of the car and ramp (as long as its behind starting line).
I know this isn't a rules clarification. Just your opinion.

Out of curiosity, the teams with wheels on the floor; was that their launch position? Just trying to get a picture in my head as to why, due to the size of their ramp, EASTstroudsburg13 stated that some teams weren't able to make mods to their car's wheel position.

[JTMess]

So to make sure I understand your take on this:
When the car is in launch position, all wheels must touch the ramp.
Prior to launch, we can adjust height and position of the car and ramp (as long as its behind starting line).
I know this isn't a rules clarification. Just your opinion.

Out of curiosity, the teams with wheels on the floor; was that their launch position? Just trying to get a picture in my head as to why, due to the size of their ramp, EASTstroudsburg13 stated that some teams weren't able to make mods to their car's wheel position.

I saw some teams last year that had very long cars (~1m) and started with the front wheels on the ground and the back wheels high on the ramp. This setup should give the theoretical best acceleration given center of gravity due to the fact that the car will then act more like a point than a three-dimensional object as it travels down the track and can follow a b-curve more precisely.

[iwonder]

Actually it wouldn't have the best velocity coming off the ramp(I assume things what you meant) because the center of mass of the vehicle is so far down the ramp that it doesn't have the same energy as a vehicle that is shorter, and this has a higher center of mass.

[Balsa Man]

iwonder has it right.
Velocity coming off the ramp is all about height- the distance over which mass falls. Brachistochrone curve, btw gets you nothing (as discussed last year) in terms of increased speed off the ramp. If the mass doesn't move around within the vehicle, it is the distance the center of mass falls- the higher the center of mass at the start, and the lower the center of mass as it comes off the ramp, the faster it's going. If you "rear-load" the mass too much, light loading on front wheels can result in a....lack of linear stability. See discussion of 'gravity supercharger' last year on a way to improve the distance you have mass falling. With significantly shorter ramps this year, the.....percent contribution of this approach is greater than last year.

[EastStroudsburg13]

Out of curiosity, the teams with wheels on the floor; was that their launch position? Just trying to get a picture in my head as to why, due to the size of their ramp, EASTstroudsburg13 stated that some teams weren't able to make mods to their car's wheel position.

Basically, their back wheels were on the ramp, and their front wheels were on the floor in front of the ramp. The team that was unable to modify it had a ramp that was so large that adding extra material in front of the ramp would put them over the maximum size.

[Teal]

Guys, I misheard the distance. I thought it was 5.5 meters, and even said, "5.5?" to the proctor, and he said yes. Then it turned out to be 8.5... And somehow, the glue had come undone, so the wheel wasn't glued on straight, and on the second run the car veered too much to the right. Oh well.

[curly657]

Just to clarify.. Shorter the ramp better the score?

Thanks
!

[JTMess]

Just to clarify.. Shorter the ramp better the score?

Thanks
!

Not necessarily. A shorter ramp will give you a lower height score, but it will also increase your speed score. You have to find the ideal height and speed combination in order to score well.

[curly657]

Just to clarify.. Shorter the ramp better the score?

Thanks
!

Not necessarily. A shorter ramp will give you a lower height score, but it will also increase your speed score. You have to find the ideal height and speed combination in order to score well.

Thanks! What height do competitors usually build their ramp to? Would 180 cm be too high?

[penclspinner]

Just to clarify.. Shorter the ramp better the score?

Thanks
!

Not necessarily. A shorter ramp will give you a lower height score, but it will also increase your speed score. You have to find the ideal height and speed combination in order to score well.

Thanks! What height do competitors usually build their ramp to? Would 180 cm be too high?

One important tip to remember is that the ramp height isn't what determines your height score. It's the height of where your vehicle is in the ready to launch position that determines the height score.

As JTMess said, you have to find the ideal height and speed combination. There's no point in asking what the optimum height is since each competitor's vehicle is unique and will perform differently.
You'll have to experiment from various launch positions to find where the optimal height is for your vehicle.