Kings Dominion construction ramps up for new roller coaster

There will never be a limit on how fast coasters can go, only a limit on what the human body can take for G-forces. Sooner or later, we'll see maglev technology on coasters and elimate wheels alltogether.

Sooner or later, somebody's gonna break 500 feet, and FINALLY do a deuling flyer. Heck, I'd settle for a 300-foot flyer, or even a coaster with a 200-foot loop.

Yeah, but the Intamin literature also says, 94 MPH and the only Intamin giga in existence doesn't quite get that fast. So maybe it will be a 297' giga. ;)

Well, I meant that we've probably seen just about as far as the amusement industry is willing to go when it comes to the price of a record-breaking coaster. :)

But it's nice to know that I am probably wrong.

Last time I checked, MF tops out at 91 mph with a 300 foot drop. If the info say 94 mph, it's probably more like a 350' height with a 330' drop.

I though we established many years ago that given the wind resistance, wheel friction, ect. that MF reached just about as fast as a coaster car could go without being launched. It could be 900 feet tall and still only reach 94 MPH, if I am understanding and recalling correctly.

This is even more exciting to me than Diamondback. Discussing the new coaster is still not making next summer get here any faster. lol. A watched pot never boils, and stuff.

Gravity is gravity. Dragster will hit 120-ish mph on the way down whether it's from a dead stop (which has happened a few times) or from being launched over.

LostKause said:
I though we established many years ago that given the wind resistance, wheel friction, ect. that MF reached just about as fast as a coaster car could go without being launched. It could be 900 feet tall and still only reach 94 MPH, if I am understanding and recalling correctly.

Something about that just doesn't sound right so I pulled out the college physics textbook from 30 years ago. At the top of the hill, the coaster has potential energy that is converted into kinetic energy as it falls down the hill. Potential energy = mgh (mass, gravity, height). This is converted into kinetic energy = 1/2 m v^2 (one half, mass, velocity squared). Friction, air resistance, etc, will use up some of the potential energy so v-max will not be obtained in the real environment. In other words, height matters. In fact, since the mass of the coaster is also important, I guess girth matters too. ;)

Also, MF"s drop is an 80 degree drop vs TTD's 90 degree drop. At straight down the coaster train presents its slimmest profile for wind resistance thus it has a higher terminal velocity then MF's 80 degree drop where the train is sidewards.

The point is that LK is wrong. A taller coaster will go faster.

I didn't know if I was right or wrong in my recollection. What is the terminal velocity of a coaster? What is the fastest a coaster can fall without being launched?

Math and science is not my thing.

I'm not so sure that a launched coaster like Dragster reaches 120 on the way down. I thought it only reached that speed at the launch to reach the top.

Where's Rideman? I think that he was the one who led me to this understanding years ago.

And let me say again, I could be wrong.

The mechanism by which the coaster reaches the top of the hill does not affect the velocity with which the coaster goes down the hill on the other side. In other words, the downward velocity will be the same if you magnetically launch a coaster to a height of 300 feet or slowly pull it up the hill with a chain. The potential energy at the top of the hill is dependent on mass, height and gravity, irrespective of the mechanism by which the coaster reached that height.

Launching has nothing to do with it, LK, that was my point.

Terminal Velocity is the speed in which the drag cancels out the force of gravity resulting in an acceleration of zero. Its affected by the mass of the object and the area that is exposed to wind resistance.

I get what LK is saying (I'm an ex-sky diver from many moons past, and we learned a thing or two about terminal velocity). What he is saying is that a coaster with a given aerodynamic profile and friction coefficient has a maximum velocity that it can travel, even in free fall. After that speed is reached, it doesn't matter from how high a distance it falls, because it simply can't ever go any faster. The only way to increase this number is to physically push the train through the air...i.e., a launch.

In other words, the downward velocity will be the same if you magnetically launch a coaster to a height of 300 feet or slowly pull it up the hill with a chain. The potential energy at the top of the hill is dependent on mass, height and gravity, irrespective of the mechanism by which the coaster reached that height.

Not quite... The potential energy will be the same, yes, but the train can have varying kinetic energy at that point depending on how fast it's moving over the top (a slow chain pull vs. a fast airtime inducing launch). The sum of potential and kinetic energy is what determines the final velocity (ignoring friction of course). Mathematically it's:

PE(top) + KE(top) = PE(bottom) + KE(bottom)

Unless you're launching from the top (like an S&S turbo drop) then the difference in falling velocity is going to be negligible. The point stands that you can still go a hell of a lot faster from 400 feet than you can from 300. Didn't they figure on Mythbusters that the terminal velocity of a car falling out of the sky was something over 300 mph? I doubt a roller coaster will be built any time soon that will actually reach terminal velocity, and even then, you'll need to wear goggles.

I imagine it would be necessary to be totally enclosed for a ride like that.

You're right, Matt. I inaccurately assumed that the launched coaster had reached it's maximum potential height and crested the hill with minimal residual velocity, similar to pulling the coaster up the hill with a chain. Any residual kinetic energy/velocity would be added to the downhill velocity (generated from the potential energy = mgh). LostKause, that is probably what you remembered concerning launched coasters. So in that sense, you were right. My apologies.

"She can't take much more of this, Captain Kirk! I can't defy the laws of physics...."

To clarify... I wasn't saying that you can achieve a higher terminal velocity by launching from the top. If the object is moving faster than terminal velocity at this point, it will then slow down to terminal velocity (assuming it hasn't hit the ground already).

What I was saying previously was simply that initial velocity at the top of a drop affects the maximum achievable velocity on the way down. This is pretty obvious if you look at a coaster with a midcourse brake. When the brake is open, the train travels faster back to the station than it would if the brake was used. Even at 300 feet tall, the initial velocity is not negligible.

And just to clarify further, If the train is launched from the bottom of a hill to the top, when it reaches the bottom again, it can't go any faster than than the maximum speed it reached during the initial launch.

(Whiny voice) "Why am I always so misunderstood?"

I already knew all the Mr Wizard stuff. Thanks, AV, for interpreting for me. :)

So, does anyone know roughly what the terminal velocity of a roller coaster falling a great distance would be, given that there is friction at the wheels, and air resistance?

Does Dragster, for example, really reach anywhere around 120 MPH during it's decent back to earth?