Statistic Factors

[Raymond333]

Why would a coaster have the same drop but a different speed? For example Millennium Force and Intimidator 305. Both 300 foot drop but one's faster. Only 3 mph difference. But also, MF is faster and longer but has a 2:20 duration while I305's duration is 3:00 minutes. This makes no sense to me. Can anyone explain?

[jarmor]

Well, since 305 was neutered...I mean altered, im sure it and mforce doesnt have the same speed anymore.

[Skramp]

Could it be the weight difference of the cars? Since mass is figured into the equation, if one set of cars weighs more than the other, that could affect it's speed. Correct?

[braztaz]

^Er, I'm not so sure if the angle of the drop has anything to do with speed.

 

EDIT: Guess he realized his mistake and deleted the post!

[let1gre]

Also, lift hill speed maybe?

 

EDIT: Where are you getting the duration times from? I just watched and compared POVs of Intimidator 305 and Millennium Force and found that I305's time from lift hill start to end of brake run was around 68 seconds, whereas the time of MF from start of lift to brake run was about 100 seconds.

[braztaz]

Also, lift hill speed maybe?

 

EDIT: Where are you getting the duration times from? I just watched and compared POVs of Intimidator 305 and Millennium Force and found that I305's time from lift hill start to end of brake run was around 68 seconds, whereas the time of MF from start of lift to brake run was about 100 seconds.

 

In the official press release, KD referred i305's ride time as 3 minutes. This means from the time you step into your seat to the time you get out. Not the actual ride.

[mightbeawannabe]

Mass, friction, and momentum, and inertia are big factors in these kind of things.

[Chroniq]

LUBRICATION

[FeelTheFORCE]

^Er, I'm not so sure if the angle of the drop has anything to do with speed.

 

EDIT: Guess he realized his mistake and deleted the post!

 

 

Actually, I'd think that would be one of the main reasons why. I305's drop is 5 degrees steeper (85 versus 80), meaning that there is less friction, causing the train to go faster.

[spaminacan11]

Could it be the weight difference of the cars? Since mass is figured into the equation, if one set of cars weighs more than the other, that could affect it's speed. Correct?

 

Mass actually would not affect the speed of a roller coaster train going up or down a hill at all. The reason for the speed difference is mainly due to friction, and wind resistance. So obviously, a steeper hill will have less friction, and therefore, less will impede on its acceleration. Of course, the speed of the lift hill also can come into play, but as the train goes, the better the lubrication and aerodynamics, the faster the train will be able to go.

[Chroniq]

^ I told you it was all about the lubrication..

 

 

 

Chris is a scientist

[DarkStitch626]

LUBRICATION

Hershey park much?

[EastCoastn07]

Yeah, mass doesn't have an effect on the speed at all. This goes back to the whole dropping an apple and a book and seeing which lands first (they both do). This can be explained by simple energy principles, potential (mgh) and kinetic (1/2mv^2). Setting them equal, and solving for velocity, the masses cancel out and you get an equation sqrt(2gh) which states that the velocity only depends on the gravity constant and the height you're dropping something from. Now this neglects friction and air resistance, so as mentioned earlier, they also have a factor on the final speed as well. Also, different areas of the Earth have different gravity constants which may affect the speed as well, but the difference is negligible in most cases.

 

Hope my elementary physics lesson helps. This kinda stuff gets etched into your brain after four years of engineering studies.

[Invertalon]

I appreciate your effort above, but your reasoning neglecting air resistance and friction make your post near pointless in terms of roller coasters, in which the three largest forces involved include gravity, friction and air resistance. You can not really eliminate these in discussion.

 

Mass is that quantity that is dependent upon the inertia of an object. The more inertia that an object has, the more mass that it has. A more massive object has a greater tendency to resist changes in its state of motion (i.e. friction and wind resistance). The same reason if you launch a ping pong ball and bowling ball at the same angle and speed, the bowling ball with travel MUCH farther.

 

Therefore, the heavier the train, the better the ability it has to overcome friction and other forces (such as air resistance).

 

There are many factors that can make two identical coasters different in speed from the other... Weight of the train, total resistance in the "system" of the train (friction in wheel bearings, types of wheels used, air resistance, etc...) along with types of lubrication among other things.

 

I305 could have better air-resistance, a greater train mass (they are different trains, after all) and a steeper drop which could lead to a quick ride. Many factors involved. Not to mention the ambient temperature (hotter air is less dense, less resistance... Cold air is more dense, more work is needed)

 

The reason one may be faster than the other at given heights and speeds, is simply which has faster average velocity given track length.

[Fooz]

I'd think that 10 years of progress in fabrication precision would have something to do with it.

[coasterlover420]

I don't think this has much more to do with physics than it does with false advertising. If you actually time these coasters logically, you'll find that any advertised time frame is usually inaccurate or scaled differently than others (i.e. from dispatch, start of lift, end of lift, etc...). TTD was advertised as a 17 second coaster, but KK was advertised as a 28 second coaster. There's no way 36 extra feet and a hill would add 11 seconds onto that coaster, they are just timed from different points.

[yankees15]

I have always wondered why Apollo's chariot and Nitro had such speed differences when their drops are almost the same. Apollo has a 210 foot drop at 65 degrees and goes 73mph, while Nitro drops 215 feet at 66 degrees going 80mph. Both rides have the same trains with the same amount of seats. Does 5 feet and 1 degree really cause a 7 mph difference?

[TheStig]

Parks can make their rides go however fast or slow they want. In fact they use the wheels to do some. Some wheels run faster then others, and mixing these wheels will give you various speeds. It's not uncommon for rides to run faster wheels during the colder months, and slower ones in the summer. I'd say about 99% of rides don't hit their advertised speed and either run faster or slower.

[Invertalon]

Wheels make a great difference in speeds.

 

You will notice during colder months at Cedar Point, they will use a higher ratio of Nylon wheels on Raptor to prevent rollbacks. Not only does it increase speed, but make the ride insanely LOUD.