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Ultimate Rollercoaster > Discussion Forums > Roller Coasters, Parks & Attractions > MF, speeeding?

MF, speeeding?

john

Posted:
4/23/00 at
9:25:12 PM

OK don't jumpp all over me if you think this is crap. but from 3 totally diferent sorces this weekend while driving through the sandusky ohio area, 2 from cp while taking some pics.. i truly heard that mf was hitting over 100mph and they were trying to slow it down before next weekend. does anyone else know anything about this at all... please do not be harsh if you do not belive this i am only asking if anyone else heard this.. i heard it from a lady at the gate at cp on easter morning, and another person taking a picture, and a friend of mine that is in good with some of the contractors.. thanks john

Re: MF, speeeding? by Jeff Tolotti at 4/23/00 11:36:46 PM

> OK don't jumpp all over me if you think this
> is crap. but from 3 totally diferent sorces
> this weekend while driving through the
> sandusky ohio area, 2 from cp while taking
> some pics.. i truly heard that mf was
> hitting over 100mph and they were trying to
> slow it down before next weekend.

Not physically possible. An initial chain speed of 16m/s was reported, which is 11mph, but some have reported it going as fast as 20mph. I worked all these into the calculations to follow.

This equation is derived from the law of conservation of mechanical energy, because the only force (barring friction and losses for the time being) acting on the train is gravity and gravity is a conservative force - meaning that its intial mechanical energy (kinetic + potential) is equal to its final mechanical energy (kinetic + potential). The angle of the descent has no effect on this hypothetical max speed. When dealing with gravity as the only force, the path from point A to point B does not matter.

Equation: Final velocity in meters per second = squareroot (two times the force of gravity in m/s/s times square root of height in meters plus the square of initial velocity in meters per second)

Vf = sqrt(2gh + V0^2)

Anyway, some quick conversions/info.

20mph = 8.9408m/s 300ft = 91.44m g = 9.80665 101mph = 45.15104

Plug them in and here's some raw numbers for you. Note that ALL of these do not take friction/losses into account, which for most coasters is a 3-5% loss coeffecient.

Velocity produced by 300' drop alone Vf = sqrt(2*9.80665*91.44) Vf = 42.35m/s = 94.73mph

Velocity produced by 300' drop plus 20mph initial velocity Vf = sqrt(2*9.80665*91.44 + 8.9408^2) Vf = 43.28m/s = 96.82mph

Initial Velocity required to achieve 101mph on 300ft drop Vf = sqrt(2gh + V0^2) Vf^2 = 2gh + V0^2 V0^2 = Vf^2 - 2gh V0 = sqrt(Vf^2 - 2gh) V0 = sqrt(45.15104^2 - 2*9.80665*91.44) V0 = 15.66m/s = 35.0262mph

As you can see, short of a chain speed of over 35mph, Millennium Force does *NOT* reach 100 miles per hour. With the speed the chain is reported to be going (higher than the chain speed the park stated, even), it maxes out at under 97mph *BEFORE* taking account friction and air resistance.

Jeff

Sorry... by Jeff Tolotti at 4/23/00 11:38:37 PM

The board doesn't seem to like when I post with lots of line breaks. Formatting gets screwed up. All the info's there though ;)

Jeff

I have been wondering... by Schrecken Schrecken Profile at 4/23/00 11:51:48 PM

Not physically possible. An initial chain speed
> of 16m/s was reported, which is 11mph, but
> some have reported it going as fast as
> 20mph. I worked all these into the
> calculations to follow. This equation is
> derived from the law of conservation of
> mechanical energy, because the only force
> (barring friction and losses for the time
> being) acting on the train is gravity and
> gravity is a conservative force - meaning
> that its intial mechanical energy (kinetic +
> potential) is equal to its final mechanical
> energy (kinetic + potential). The angle of
> the descent has no effect on this
> hypothetical max speed. When dealing with
> gravity as the only force, the path from
> point A to point B does not matter.
> Equation: Final velocity in meters per
> second = squareroot (two times the force of
> gravity in m/s/s times square root of height
> in meters plus the square of initial
> velocity in meters per second) Vf =
> sqrt(2gh + V0^2) Anyway, some quick
> conversions/info. 20mph = 8.9408m/s 300ft =
> 91.44m g = 9.80665 101mph = 45.15104 Plug
> them in and here's some raw numbers for you.
> Note that ALL of these do not take
> friction/losses into account, which for most
> coasters is a 3-5% loss coeffecient.
> Velocity produced by 300' drop alone Vf =
> sqrt(2*9.80665*91.44) Vf = 42.35m/s =
> 94.73mph Velocity produced by 300' drop
> plus 20mph initial velocity Vf =
> sqrt(2*9.80665*91.44 + 8.9408^2) Vf =
> 43.28m/s = 96.82mph Initial Velocity
> required to achieve 101mph on 300ft drop Vf
> = sqrt(2gh + V0^2) Vf^2 = 2gh + V0^2 V0^2 =
> Vf^2 - 2gh V0 = sqrt(Vf^2 - 2gh) V0 =
> sqrt(45.15104^2 - 2*9.80665*91.44) V0 =
> 15.66m/s = 35.0262mph As you can see, short
> of a chain speed of over 35mph, Millennium
> Force does *NOT* reach 100 miles per hour.
> With the speed the chain is reported to be
> going (higher than the chain speed the park
> stated, even), it maxes out at under 97mph
> *BEFORE* taking account friction and air
> resistance. Jeff

For a while now I have been wondering what would stop a coaster with such height from exceeding 100mph, but then I really stink at math anyway. BTW, Jeff, by your calculations exactly how tall (or how long a drop) would a coaster have to be/have to hit 100mph naturally, that is by the force of gravity alone? I know that I have put my car in neutral going down a mountain side (at a much milder incline than any coaster) and have hit 85 or 90mph, so I guess it is the length of the descent rather than its steepness that determines the buildup of speed, right (and the weight of that which is falling - per Newton's calculations)? But then in a car you would have to figure in the speed at which you crest the hill, as in the MF scenario. Just wondering.

Re: I have been wondering... by Jeff Tolotti at 4/24/00 1:54:51 AM

> BTW, Jeff, by your
> calculations exactly how tall (or how long a
> drop) would a coaster have to be/have to hit
> 100mph naturally, that is by the force of
> gravity alone?

102m, or just under 335 feet.

> I know that I have put my car
> in neutral going down a mountain side (at a
> much milder incline than any coaster) and
> have hit 85 or 90mph, so I guess it is the
> length of the descent rather than its
> steepness that determines the buildup of
> speed, right (and the weight of that which
> is falling - per Newton's calculations)?

Mass cancels out in this case. Neglecting resistance, a paperclip falls at the same speed as a person, etc. Angle of descent factors in *only* when dealing with resistance and friction.

Jeff

MF's Lift Speed by Jim Disney at 4/24/00 11:50:23 AM

The lift speed is 14.5ft/sec. This equates to 9.88MPH. I hope this clears things up. A normal coaster lift is 5-6ft/sec or 4.09MPH. MF's lift also does NOT slow as it crests the hill as is the norm with chain driven lifts.

JD

The Southern California Coaster Club

Re: MF, speeeding? by Kevin Reid at 4/24/00 12:51:09 PM

So call the guy a liar for 3mph. It would be different if he was saying,"150-200". Give the guy a break.

Regards,

Kevin Reid

PCW Junkies On Ride Photos of Fear

Re: MF, speeeding? by Shaggy Shaggy Profile at 4/24/00 3:26:10 PM

By no means am I able to quote advanced physics equations or challenge them, however I can relate something that I have heard form more than 3 sources.

T - R - I - M

Just rumor at this point. Here's hoping it's not true.

Shaggy

Re: MF's Lift Speed by Jeff Tolotti at 4/24/00 3:36:55 PM

> The lift speed is 14.5ft/sec. This equates
> to 9.88MPH. I hope this clears things up. A
> normal coaster lift is 5-6ft/sec or 4.09MPH.
> MF's lift also does NOT slow as it crests
> the hill as is the norm with chain driven
> lifts.

My understanding is that it was stated to be 16f/s at NoCoasterCon. Not really important though. I had originally done the calculations because someone said they heard the lift was going 20mph and the ride was reaching 101mph. So I used that figure to refute that claim. Naturally with a slower lift it'll go even SLOWER than my figures show.

Jeff

Re: MF, speeeding? by Jeff Tolotti at 4/24/00 3:40:48 PM

> By no means am I able to quote advanced
> physics equations or challenge them, however
> I can relate something that I have heard
> form more than 3 sources. T - R - I - M
> Just rumor at this point. Here's hoping it's
> not true. Shaggy

I read that the brackets are in place on the last half of the ride, but no trims yet. I can't really imagine them trimming the first half of the ride, given that I don't think it'll be going all that fast over the third hill in the first place...

Jeff

Re: MF, speeeding? by Jeff Tolotti at 4/24/00 3:43:32 PM

> So call the guy a liar for 3mph. It would be
> different if he was
> saying,"150-200". Give the guy a
> break. Regards, Kevin Reid

I wasn't the one who made a post about a few miles per hour in the first place. He wanted to know if it was true. It wasn't, and I showed why.

Jeff

Re: MF, speeeding? by john at 4/24/00 10:33:12 PM

> OK don't jumpp all over me if you think this
> is crap. but from 3 totally diferent sorces
> this weekend while driving through the
> sandusky ohio area, 2 from cp while taking
> some pics.. i truly heard that mf was
> hitting over 100mph and they were trying to
> slow it down before next weekend. does
> anyone else know anything about this at
> all... please do not be harsh if you do not
> belive this i am only asking if anyone else
> heard this.. i heard it from a lady at the
> gate at cp on easter morning, and another
> person taking a picture, and a friend of
> mine that is in good with some of the
> contractors.. thanks john i understand your view on this with the math and all. but i must say that even Goliath was said to have been running over 90 mph when testing.. so that is why i was asking any views. thanks guys. play nice.

Re: MF, speeeding? by Flare at 4/26/00 1:44:05 AM

Kevin, Mind if i ask why you're the guy jumping on someone for very *OBJECTIVELY* providing formulaic discourse on an issue that was initiated by someone curious, and ASKING for possibility of confirmation on what he had heard???????!

Just curious.

Regards Dave

p.s. Thanks Jeff!...lol

> So call the guy a liar for 3mph. It would be
> different if he was
> saying,"150-200". Give the guy a
> break. Regards, Kevin Reid

Re: MF, speeeding? by OhioMike at 4/26/00 2:17:42 AM

Are you saying that a direct line going frome point A to Point B at any angle will, force the same amount of speed. Despite more friction in a longer version. If point a and b are further apart, which would be the case at lets say 60 degrees, then with less time for friction at 80 dgrees.

Re: MF, speeeding? by Jeff Tolotti at 4/26/00 5:07:30 AM

> Are you saying that a direct line going
> frome point A to Point B at any angle will,
> force the same amount of speed. Despite more
> friction in a longer version.

No, I said "When dealing with gravity as the only force, the path from point A to point B does not matter." Friction creates a force. And before that, I said "barring friction and losses for the time being."

Jeff

Re: I have been wondering... by OhioMike at 4/26/00 11:21:22 PM

> , so I guess it is the
> length of the descent rather than its
> steepness that determines the buildup of
> speed, right (and the weight of that which
> is falling - per Newton's calculations)? But
> then in a car you would have to figure in
> the speed at which you crest the hill, as in
> the MF scenario. Just wondering.

Well if you look at the fact that the SOB at a far less angle than Magnum XL 200 but a tad bit higher goes a tad bit faster. Yes the speed will be the same on hieght, no matter how you change the degree of the angle of the drop. SOB together with Magnum is a good example to me. All I was saying before was with a steeper hill, there is a shorter run from point a to b, makeing for less friction.