The one and only NoLimits 2 Topic

Wolfram Alpha says 73m/s or 160mph with Cd=.15, air density of 1.225 kg/m^3, mass 4000kg and 900ft of freefall. The NL speed would be lower due to rolling resistance and the train is far from a streamlined body but not significantly lower due to the input speed provided by the lift mechanism (which would have to be considerable considering the height.

Originally posted by Bottom_Feeder_13

which would have to be considerable considering the height.

You do realize you just challenged cool5 to make a 900 foot tall jet coaster with a 1 mph lift, right?

with 45 chain lifts and 6 miles long

Originally posted by NightwindElf

Originally posted by Bottom_Feeder_13

which would have to be considerable considering the height.

You do realize you just challenged cool5 to make a 900 foot tall jet coaster with a 1 mph lift, right?

[hyyyper]

Originally posted by Pockets

Just for a quick thought experiment, Trackwalker...

m*g*h=1/2*m*v^2

I have to guess on "m", but the internet says that a single car weighs between 400 and 600 kg, so let's say 4000 kg for an average train.

so

4000 kg *9.81 m/s^2* 274.32 m = 1/2*4000 kg* v^2

and

v=73.36 m/s, or about 164 mph. (is it just me, or does that seem low)

But that's without air friction.

For that, I need to make more assumptions. Says the internet, a rollercoaster train has the approximate dimensions of 1.2 m x 1.1 m. So A= 1.32 m^2. Also the drag coefficient for a long, streamline body is .1, so assuming slightly less than optimally smooth, let's say Cd= .15. Finally, the density of air is normally around 1.2 kg/m^3.

Now, I don't feel like doing differential equations, but the research is done, for anyone who wants to continue.

You do not need the mass value, silly.
The mass is in both the potential and kinetic energy so it can be removed from the equation.
It's strange that you know those formulas, but have forgotten free fall speed does not depend on mass.

Haha, oops!

But you'll need it for the air resistance equation.

[hyyyper]

If I recall correctly, air drag is 1/2*rho*A*cd*v^2, which is again independent of mass. Now, if you want rolling resistance for a non-vertical drop, then you'll need mass.

[mkingy]

Originally posted by hyyyper

If I recall correctly, air drag is 1/2*rho*A*cd*v^2, which is again independent of mass. Now, if you want rolling resistance for a non-vertical drop, then you'll need mass.

I concur!

Maybe I am mistaken, but here's my logic:

a=Fnet/m

in which Fnet is m*g-Cd*v

then differentiate to go to (in TI-89 speak)

int(1/(g-Cd*v/m),0,v)=t

then, use u-substitution where u=g-Cd*v/m

ending up that dv=-m/Cd*du

and that

(-m/Cd*ln(abs(g-Cd*v/m),0,v)=t

then solve for v by doing e^...

and you get

v=m*g/Cd-m*g/Cd*e^(-Cd/m*t)

Then you can approximate the amount of time it takes to fall just by assuming normal gravitational acceleration and solve for v.


Unless...

That Cd in this equation isn't the one I looked up. Because the equation to get that should take into account frontal area and air density.

Heck, maybe I'm totally wrong. I gave up aeronautical engineering for a reason. [sillyme]

The answer is 12.

7 only on a Tuesday

[Oscar]

Everyone Should Like This Page:

https://www.facebook.com/NLCoaster2

[Turbo]

pfft, done.

Is it official?

No.

[Metazoanhaddock]

its quite refreshing seeing an ACTUAL INTELLECTUAL DISCUSSION taking place on these forums...props to all the engineering majors here. (note: im an engineering major =P)(but not to come off sounding pretentious)

[Turbo]

Originally posted by Freddie

Originally posted by dcs221

Is it official?

No.

Well, They said "It will be released this year for sure."

Take that how you may, I'm staying optimistic, but realistically their release dates are on Valve time, so it could still be a few years from now.

However I am seriously hoping they follow through this time

Right but the official page is here: https://www.facebook.com/nolimitscoaster2

the other one is just link-baiting. I'm sure I'll get banned or at the very least my posts deleted but whatever.

[Turbo]

Freddie: This is where I get my info

http://www.nolimitscoaster.de/index.php?page=news

Right I wasn't disputing that. I was disputing that the facebook page linked here is not official.

Originally posted by Freddie

Right but the official page is here: https://www.facebook.com/nolimitscoaster2

the other one is just link-baiting. I'm sure I'll get banned or at the very least my posts deleted but whatever.

Freddie, that's not official. Casper and I moderate that page. It's a fan page.

Ah ok, figured since that one has been around forever and updates relatively quickly it was the real one. Still, I'm assuming you guys don't embed ad links to get to it either.

[Turbo]

Originally posted by Freddie

Right I wasn't disputing that. I was disputing that the facebook page linked here is not official.

oh lol, my bad, I misunderstood

[Oscar]

Freedie, I don't see either one having ad links.

so they did give a october update with pics


https://scontent-a-ord.xx.fbcdn.net/hph ... 5266_n.jpg