MK Big Thunder Mountain to receive full retrack

[Skibum1970]

Ah, but is it? Do not the LIMs that propel the trains into and out of the stations create temporary, focused, gravitic anomalies that might affect how Earth's normal gravity speeds up/slows down the trains on the track?

Even reading this made my head hurt. Why do I feel like I go faster in the back of the coaster train? Can't happen, right? However, I always think I do. Or that I go fast longer. Maybe it is that I spend more time facing down at top speed whereas the front of the train spends more time moving on to the next element.

I do seem to remember that lighter trains don't always make it through the circuit when the weather is cooler and that the weight of the train and passengers is needed to push into the various elements. However, I'm not an engineer and truly know next to nothing, aside from what I read.

 

[flynnibus]

Even reading this made my head hurt. Why do I feel like I go faster in the back of the coaster train? Can't happen, right? However, I always think I do. Or that I go fast longer.

You don't actually go any faster than the other seats. How do you know this? The distance between your seats doesn't change. But what is different is when and how you experience the changes in speed (acceleration and direction). The guy at the front just gets pushed down the hill.. while the guy at the back gets pulled up and over the hill crest. The train doesn't stretch.. the difference is how you experience the forces.

It's the changes in direction (acceleration) that are the thrills - not as much the speed. Just like cruising at 30k ft at 600mph isn't that thrilling.. even tho you are going 10x faster than you normally experience travel. Constant speed is boring unless you are psychologically stimulated by watching things race by you.

 

[ToTBellHop]

Anecdotally I think coasters are faster on a cold day.

Colder air is denser, which should slow it down. I don't think rider weight is a big deal as a bunch of you have said.

The wheels usually have a layer of urethane on them where they touch the track. When cold they will deform less and roll more easily, I'll bet this is the biggest difference. Maybe the performance of bearings/grease when cold.

Coasters are slower in the cold. That’s why they’re more likely to valley. Most coasters won’t operate below a certain temperature.

 

[osian]

Even reading this made my head hurt. Why do I feel like I go faster in the back of the coaster train? Can't happen, right? However, I always think I do. Or that I go fast longer. Maybe it is that I spend more time facing down at top speed whereas the front of the train spends more time moving on to the next element.

You're on the right lines. It's because the front and back of the train experience the same elements at different speeds. Approaching the apex of a hill, the back will be accelerating upwards towards to the apex because the centre of gravity of the train has passed the apex and is accelerating down, and you feel like you're being whipped over the top. In the front, you slowly go over the apex as the centre of gravity is still going uphill and is therefore slowing down, and you only gradually increase speed as you go down.

But obviously, at any point in time, every part of the train is travelling at the same speed. But they're travelling over different parts of the track. As with Soarin, there is only one "sweet spot" where the acceleration feels "right" or natural. That will be in the centre of the train, or rather where the centre of gravity is.

 

[flynnibus]

You're on the right lines. It's because the front and back of the train experience the same elements at different speeds.

Not at different speeds - just different velocity vectors.. so they experience different accelerations. It's actually the fact they are the same speed that creates the different experience.. as the rider in the back is dragged to stay at the same speed as the front. The train doesn't change length - so there is no way for one seat to actually go at a higher speed than another seat. They just experience different accelerations.

 

[MisterPenguin]

Ah, but is it? Do not the LIMs that propel the trains into and out of the stations create temporary, focused, gravitic anomalies that might affect how Earth's normal gravity speeds up/slows down the trains on the track?

Don't forget y'all weigh less at the top of a hill being further away from Earth's gravity.

Lessee, doing the Einstein equations.... working... working.. y'all and the trains are 0.00038% lighter.

 

[Touchdown]

Where you are on the train however does change how fast you are going on that specific section of track. Take the top of a lift hill, the front of a train typically crests the hill powered by the lift hill but by the time the back of the train crests a majority of the train’s mass has done so and the train is being accelerated by gravity so the back of the train crests at a faster speed. You just have to think fourth dimensionally. The back of the train will be traveling faster through a track portion then the front of the train when the train itself is accelerating through a feature and slower if it’s decelerating. That’s why the back is better for airtime and most laterals. The back always is traveling faster over the top of a hill, so is “whipped” more resulting in stronger G-Forces, most turns typically have a downward slope so same rule applies (but any turn that raises in elevation will be wilder in the front.)

 

[phillip9698]

Not at different speeds - just different velocity vectors.. so they experience different accelerations. It's actually the fact they are the same speed that creates the different experience.. as the rider in the back is dragged to stay at the same speed as the front. The train doesn't change length - so there is no way for one seat to actually go at a higher speed than another seat. They just experience different accelerations.

He stated different speeds at different points of the track. The front of the coaster 100% goes over the top of the hill at a different speed than the back of the coaster does.

 

[flynnibus]

The front of the coaster 100% goes over the top of the hill at a different speed than the back of the coaster does.

Edited: Ok, if you want to compare how two DIFFERENT positions experience a single point in the track, yes, they both experience that reference point different. But I think you just muddy the water by trying to compare two different positions at different points in time. It's not really relevant to measuring the train speed or its variation - that is variation due to different positions.

 

[UNCgolf]

It physically can not. The front of the train and the back of the train are hard connected. They can not move at different speeds. What they can do is move in different DIRECTIONS because they are not constrained to a single rigid axis.

You are confusing what you feel from differences in acceleration - because the different seats are being pushed in different directions due to the hill crest. The guy in the back gets the acceleration as he nears the crest.. while the guy in front gets the acceleration as he's already facing down the hill. Different experiences - same actual speed. The experiences differ because the change in direction is different.

Drive in a straight line at 35mph.
Then turn while maintaining 35mph.

Completely different experiences - but the same speed. Because while the speed is constant and the same between both examples, the acceleration isn't the same.

Velocity is a vector - speed is just distance over time.

This is simple dynamics folks.. its just not the specifics most people think about in day to day life.. and why Science teachers can always come up with cool demonstrations to wow people with physics.

They wouldn't be traveling at different speeds; he was referencing two different points in time.

 

[flynnibus]

They wouldn't be traveling at different speeds; he was referencing two different points in time.

meh... comparing different things in a discussion of 'is it equal' just muddies the water

The guy at the front of the train experiences the ride differently than the guy at the back - every ride cycle. And not because the guy at the front goes faster - but because their position is different hence their ride profile is different.

I mean, yes, it's correct that that if you compare two different points in time, you get different absolute references - but you're also comparing different things. Just confuses things.

 

[Ayla]

Even reading this made my head hurt. Why do I feel like I go faster in the back of the coaster train? Can't happen, right? However, I always think I do. Or that I go fast longer. Maybe it is that I spend more time facing down at top speed whereas the front of the train spends more time moving on to the next element.

I do seem to remember that lighter trains don't always make it through the circuit when the weather is cooler and that the weight of the train and passengers is needed to push into the various elements. However, I'm not an engineer and truly know next to nothing, aside from what I read.

The back does go faster - ie, the whip effect.

 

[Ayla]

Coasters are slower in the cold. That’s why they’re more likely to valley. Most coasters won’t operate below a certain temperature.

Yep. Once the grease/oil melts on the tracks with use/warm temps, they marginally speed up.

 

[osian]

It's all the same thing, just a question of trying to describe it! We all know that the back doesn't travel faster than the front. Coasters are not faster at the back. This is impossible.

But different people at the front and back will experience the same elements at different speeds, forces and times. But different elements and forces at the same times and speeds. What is impossible is different speeds or the same elements at the same times!

When people say it feels faster at the back, that literally refers to speed only, so that's why I talked about speed. But they might be misidentifying more intense forces as increased speeds, or perhaps just lumping together all the feelings and labelling them as speed. 20mph around a tight corner, or an acceleration from 0 to 30mph in 2 seconds, will feel more intense than a constant 40mph along a straight section, but people may describe the former as feeling faster.

 

[osian]

Yep. Once the grease/oil melts on the tracks with use/warm temps, they marginally speed up.

Within the wheel bearings.

 

[flynnibus]

When people say it feels faster at the back, that literally refers to speed only, so that's why I talked about speed. But they might be misidentifying more intense forces as increased speeds, or perhaps just lumping together all the feelings and labelling them as speed. 20mph around a tight corner, or an acceleration from 0 to 30mph in 2 seconds, will feel more intense than a constant 40mph along a straight section, but people may describe that as feeling faster.

Because 'acceleration' is generally misunderstood and poorly labeled by the lay.

What gives you thrills on a coaster is the twisting, the turns, the air time, the dropping and climbing over hills. The lay talk about 'going fast' - but what the real thing is all that CHANGING direction is actually what is the thrill on coasters.. that's what gives you the G-forces, the air-time, the sensations. That's acceleration - a change in your direction and/or speed - not the speed itself.

Speed on its own has no sensation besides wind resistance.. it's the sensation you get going past something at different speeds that gives you that rush. Like racing past a bolder that feels close to you.. it's because the bolder is basically not moving, and you are.

And the lay use of the words are generally fine... except when someone is trying to quantify why the ride feels different and trying to use an inaccurate speed measurement to justify their belief.

When a roller coaster gets significantly smoother, the amount of change you feel will decrease.. it will feel less intense because you're not being subjected to all those minor shifts.

10mph will feel really slow until someone slams on the brakes.. same thing, just exaggerated

 

[osian]

There was an infamous Open University episode, called The Jerk and the Jounce, using various rides including Nemesis to illustrate velocity, the rate of change of ve!ocity (acceleration), the rate of change of acceleration (jerk) and the rate of change of jerk (jounce). I got my head around Jerk (which explains why something can be jerky - because it's a rapid change of acceleration) but I think I checked out on Jounce!

 

[MisterPenguin]

Even reading this made my head hurt. Why do I feel like I go faster in the back of the coaster train? Can't happen, right? However, I always think I do. Or that I go fast longer. Maybe it is that I spend more time facing down at top speed whereas the front of the train spends more time moving on to the next element.

You're getting close.

Imagine the front of the train (we'll call it "A") cresting at the top of the hill. A is going at about 5 MPH. The last vehicle (we'll call "Z") is also going at 5 MPH being pulled halfway up the lift hill.

As A goes over the crest, vehicles B and C also approach and start to go over the crest.

Now, with A, B, and C over the crest, gravity pulls them down. They start accelerating. They get to 10 MPH, then 20 MPH.

While that's happening, Z starts to crest at the same velocity of A, B, and C. First 10 MPH, then 20 MPH.

When Z crests the hill, Z is going now as fast at A, B, and C, which are now going 40 MPH (gravity's acceleration makes things go faster and faster).

So, now, Z starts the decline down the hill at 45 MPH. Z is not only subject to gravity, but is being pulled by the vehicles in the front.

A, B, and C had gently crested the hill. Z, however, is being yoinked over it for some air time.

Meanwhile, A, B, and C are no longer descending. The track has flattened out. They're on a straightaway at 45 MPH. Big deal. Cars go faster.

But with Z being yanked over the crest and down the hill, Z has a different experience that *feels* faster because of the layout of the track (i.e., declining).

Everything in motion stays in motion unless acted upon an outside force. But when things alter the course, it is felt as a force. When Z crests the hill, Z is going as fast as A, B, and C. But the change in direction of the tracks (in Z's case, going down) is such a force (or, sudden lack of force free-falling in zero G). While going at the same speed as A, B, and C; Z feels the forces differently because it's going down at 45 MPH, but A, B, and C are leveling out. Different forces. Same velocity.


(BTW, physicists use "force" and "acceleration" interchangeably. So, when they say the Earth is accelerating us up, they mean the earth is applying a force upwards keeping us from sinking to the center of the Earth.)

 

[MisterPenguin]

There was an infamous Open University episode, called The Jerk and the Jounce, using various rides including Nemesis to illustrate velocity, the rate of change of ve!ocity (acceleration), the rate of change of acceleration (jerk) and the rate of change of jerk (jounce). I got my head around Jerk (which explains why something can be jerky - because it's a rapid change of acceleration) but I think I checked out on Jounce!

Applying the brake of a car is acceleration (negative). Hitting it harder because of a vehicle about to slam into you is jerk. The sudden front end collision causing a complete stop is jounce.

 

[Nunu]

Just rode it.
Definitely smoother and quieter, while still exciting.

The new cushioning of the seats and sides are appreciated. Also the new rubbery material reduces sliding and banging against your ride companion. Didn't feel a speed reduction from how it was before.

An overall improvement, imo.