200 mph RC Car

Lobber · Post by **Lobber** » Sat Sep 17, 2005 10:21 am

No, for real, not to scale 200 mph, but really going 200 mph!

http://www.fazed.org/video/view/?id=96

Unix · Post by **Unix** » Sat Sep 17, 2005 10:26 am

That's pretty cool

Tricord · Post by **Tricord** » Sat Sep 17, 2005 10:39 am

"About to go Doppler on your a$$"

CDN_Merlin · Post by **CDN_Merlin** » Sat Sep 17, 2005 11:28 am

not even a real 200mph, cheating by usign centrifugal(sp?) force/ how bout 200MPH on a straight line?

DCrazy · Post by **DCrazy** » Sat Sep 17, 2005 11:35 am

There's no such thing as centrifugal force, it's centripetal. And the car's tangential velocity is indeed 200 MPH; if it were to escape its circular path it would shoot out at a solid 200.

BigSlideHimself · Post by **BigSlideHimself** » Sat Sep 17, 2005 11:44 am

Fake.

BUBBALOU · Post by **BUBBALOU** » Sat Sep 17, 2005 12:09 pm

BigSlideHimself wrote:Fake.

spoken like a true idiot

---------------------------------
A standard Glow R/C can do about 80MPH ..now just add a two speed (stock) gearbox and it now can easily get to 140. So from the perspective of your lint covered bellybutton why is it hard to see that with just a little benchwork you can easily achieve 200..

Go buy one and learn the error in your ways..

Or take the Mobi challenge and STFU

Unix · Post by **Unix** » Sat Sep 17, 2005 12:15 pm

DCrazy wrote:There's no such thing as centrifugal force, it's centripetal. And the car's tangential velocity is indeed 200 MPH; if it were to escape its circular path it would shoot out at a solid 200.

Now, that would be cool.

Iceman · Post by **Iceman** » Sat Sep 17, 2005 12:22 pm

Wow, thats incredible and totally cool. Its amazing that the car doesn't come apart at that speed.

BigSlideHimself · Post by **BigSlideHimself** » Sat Sep 17, 2005 12:33 pm

BUBBALOU wrote:
BigSlideHimself wrote:Fake.
spoken like a true idiot

Nice composure there man. It was a joke. I'd hate to see how you get along with people in the real world.

Krom · Post by **Krom** » Sat Sep 17, 2005 12:35 pm

Heh! I could just imagine about 500 people sitting there with their heads spinning following the car.

Sergeant Thorne · Post by **Sergeant Thorne** » Sat Sep 17, 2005 2:21 pm

BigSlideHimself wrote:Fake.

You didn't get that, Bubbalou? I fell out of my chair laughing! I guess there's just no appreciation for concise, invisible humor anymore...

Personally I wasn't impressed by their RC. It's kind of neat, seeing just how fast that thing starts to go, but the title got my hopes up. I'm convinced that the centrifugal force augments the acceleration. That's cheating.

www.m-w.com wrote:centripetal: proceeding or acting in a direction toward a center or axis

centrifugal: proceeding or acting in a direction away from a center or axis

snoopy · Post by **snoopy** » Sat Sep 17, 2005 2:26 pm

Speaking of centripital force... did you see how the guy hooked the cord in somehow? I bet if he didn't he wouldn't have been strong enough to hold it. (Besides getting really freakin dizzy.) I'd bet the cord was seeing 200 lbs+ of force

Dedman · Post by **Dedman** » Sat Sep 17, 2005 2:26 pm

Now if only they could remove the tether (and all the parasite drag that comes with it), they might actually have something.

DCrazy · Post by **DCrazy** » Sat Sep 17, 2005 2:43 pm

Sergeant Thorne wrote:I'm convinced that the centrifugal force augments the acceleration. That's cheating.

I'll say this again. There is no such thing as centrifugal force. You can ask anyone who has taken an Intro to Physics course and they will tell you the same thing. Centripetal force causes bodies to remain in circular motion. The vector of centripetal force points towards the center of rotation, and the velocity of the object points straight forward. Thus, all centripetal force does is change the object's direction of motion, NOT its speed in that direction. If centrifugal force existed (i.e. a force that pointed away from the center of rotation) then the object would spiral away.

What provides the centripetal force in this example is the force of friction on the car (and possibly the guardrail if the car is running against it). If the track is sloped in towards the middle, like a NASCAR track, then the force of gravity provides a component of the centripetal force as well. The guy in the center starts the car going in circular motion, and the force of friction (mu_k * Fn, where mu_k = the coefficient of friction and Fn = the car's weight) causes the car to stay on the track. If the car travels fast enough where it exerts enough forward force to overcome that force of kinetic friction, then the car will smash facefirst into the guardrail.

BUBBALOU · Post by **BUBBALOU** » Sat Sep 17, 2005 3:48 pm

Oh I got it but you missed mine, I even added a

[edit] and I was replying to more than one DBB'r

Iceman · Post by **Iceman** » Sat Sep 17, 2005 4:05 pm

TouchÃ©!

WarAdvocat · Post by **WarAdvocat** » Sat Sep 17, 2005 5:17 pm

Sergeant Thorne wrote:I'm convinced that the centrifugal force augments the acceleration. That's cheating.

Actually, DCrazy is right...So-called centrifugal "force" is an illusion created by centripedal acceleration. However, it is quite a powerful illusion, and for the purposes of everyday conversation, it's usually unnecessary to get too technical. If you were going to play a game of dodgeball in a spinning 'wheel'-type space station, it might be necessary...but not here.

Incidentally, if my eyes don't deceive me, it appears that the car is actually running perpendicular to the ground on that strip of metal.

DCrazy · Post by **DCrazy** » Sat Sep 17, 2005 5:19 pm

Yeah the only reason I delved into such a technical discussion was because it proves that under its own power the car can indeed reach 200 MPH.

roid · Post by **roid** » Sat Sep 17, 2005 9:01 pm

perhaps some are thinking that the cable is getting increasingly shorter every rotation as it wraps around the central pole - that'd slingshot it, yes?

but it's not doing that.

my brother and i just sat here in awe as we watched that video, never seen anything like it.

Topher · Post by **Topher** » Sat Sep 17, 2005 9:32 pm

After watching that video, I can think of at least 8 ways someone could die or lose an appendage.

Sergeant Thorne · Post by **Sergeant Thorne** » Sat Sep 17, 2005 9:38 pm

I guess I stand corrected. What you're saying seems to make sense, DCrazy; I'm going to look into it.

roid wrote:perhaps some are thinking that the cable is getting increasingly shorter every rotation as it wraps around the central pole - that'd slingshot it, yes?

Not what I was thinking. In fact I noticed what may have been the cord stretching a little as the thing picked up speed. That would be cool if they did that, though!

Bubbalou, I was being sarcastic. "Fake." a joke does not make.

Mobius · Post by **Mobius** » Sat Sep 17, 2005 10:34 pm

WarAdvocat wrote:If you were going to play a game of dodgeball in a spinning 'wheel'-type space station, it might be necessary...but not here.

No, that would be the Coriolis Force you're confusing there.

Centripetal "gravity" is indistinguishable from real gravity. The only difference is that dropped items follow a curving path to the floor (as seen by the dropper), not a straight line.

BigSlide, don't stress over Bubba's latent "goin' postal" tendencies. He shows these personality flaws pretty regularly. Take him with several grains of salt. I do.

Just keep remembering that only fools stoop to argumentum ad hominen. Mostly it's a last resort - but for Bubba, it's the first thing he does.

Tricord · Post by **Tricord** » Sun Sep 18, 2005 7:11 am

Mobius wrote:Centripetal "gravity" is indistinguishable from real gravity.

Let's celebrate people. Mobi said something insightful!

They are using the cable to minimise the length of their runway (by going round in circles they have an endless runway, plus, the rotational movement induced by the cable ensures the car follows a given track without deviating due to wind or other irregularities).

Yes, the car reaches 200mph on it's own.

Having said that, it's not so impressive after all. Some moving parts in machinery reach much higher peak speeds than that. Rotation is in some way cheating, due to the extra guidance provided by the cable. It would be way off trajectory before it could even reach a fraction of 200mph in a straight line.

Oh well. Next random fact?

BUBBALOU · Post by **BUBBALOU** » Sun Sep 18, 2005 8:02 am

watch the Glow R/C carefully...

At the start it is almost a foot away from the wall and when it speeds up it comes almost to the edge (about 4"). Just think about when that cable snaps on occasion!!

WarAdvocat · Post by **WarAdvocat** » Sun Sep 18, 2005 10:14 am

Mobius wrote:No, that would be the Coriolis Force you're confusing there.

FU

I didn't actually explicitly confuse anything...(although you ARE actually right, you made an assumption!)

Money! · Post by **Money!** » Sun Sep 18, 2005 1:16 pm

Krom wrote:Heh! I could just imagine about 500 people sitting there with their heads spinning following the car.

lol

AceCombat · Post by **AceCombat** » Sun Sep 18, 2005 5:47 pm

HOLY FOSHIZNIT!!