roller coaster

Dragon Khan at Port Aventura, Spain

Roller Coaster – an amusement ride developed for amusement parks. A specialized railroad system, a roller coaster consists of a track that rises in designed patterns, sometimes with one or more loops that briefly turn the rider upside down. Most roller coasters have multiple cars in which passengers sit and are restrained.

The earliest amusement parks and roller coasters in the United States were built on Coney Island in New York during the late 1800s and early 1900s. More than 30 roller coasters were built on the island from 1884 through the 1930s. Built in 1927, the Cyclone Roller Coaster, was among the first and the most popular coasters on the island.

Roller Coaster (images) – features that make roller coasters thrilling and the physics that underlies the thrills.


  • Steel – a roller coaster with track consisting of steel tubes or rails. Occasionally steel roller coasters will use wood structures to support the steel track, this does not have an affect on its steel status.
  • Wood – a roller coaster with track consisting of layers of wood. Occasionally wooden roller coasters will use steel structures to support the wooden track, this does not have an affect on its wooden status.
  • Möbius – The two tracks are continuous forming a single circuit or ‘Moebius Loop’.
  • Passenger Restraints – may include headrest, individual lap bar (hydraulic, ratcheting, single position), shoulder harness, seatbelt

Track layouts include: Circular Gravity Railway, Cyclone – roller coaster whose track layout is designed after the legendary Coney Island Cyclone, Double Figure Eight – Figure eights are side-by-side, Out and Back, Shuttle Loop, Single Helix (center, left or right), Terrain, Twister
What’s the problem?
Loops – In the early days of roller coaster loops, circular loops were used. There were a variety of problems, some of which resulted in fatalities, as the result of the use of these circular loops.

  • Ask – Coaster cars entering circular loops at high speeds encountered excessive normal forces that were capable of causing whiplash and broken bones. Efforts to correct the problem by lowering entry speeds resulted in the inability of cars to make it around the entire loop without falling out of the loop when reaching the top. The decrease in speeds as the cars ascended the large circular loop resulted in coaster cars turning into projectile cars (a situation known to be not good for business). What were some of the problems that could be resolved by changing the shape of the track?
  • Imagine – What other track shapes could be constructed? Since clothoid loops have a continually changing radius, the radius is large at the bottom of the loop and shortened at the top of the loop. The result is that coaster cars can enter the loops at high speeds; yet due to the large radius, the normal forces do not exceed 3.5 G’s.
  • Plan, Create – The solution to the problem involved using low entry speeds and a loop with a sharper curvature at the top than at the bottom. At the top of the loop, the radius is small thus allowing a lower speed car to still maintain contact with the track and successfully make it through the loop.
  • Improve – The clothoid loop is a testimony to an engineer’s application of the centripetal acceleration equation – a = v2/R. Now that’s physics for better living!

That’s engineering

  • acceleration – a vector quantity that is defined as the rate at which an object changes its velocity. An object is accelerating if it is changing its velocity.
  • clothoid – a section of a spiral in which the radius is constantly changing. Unlike a circular loop in which the radius is a constant value, the radius at the bottom of a clothoid loop is much larger than the radius at the top of the clothoid loop.

Engineering ideas

  • force, acceleration, circular motion, entry speed

Do It
Challenges for you to work on…

  • Marble Roller Coaster – build 20′ long roller coasters. Watch the video (0:20) to see some examples.
  • Virtual Field Trip (vft) – make a documentary virtual field trip to an amusement park featuring a roller coaster, Include information about the structure of the ride as well as pictures and video of the experience.

Learn more…

  • Project-Based Engineering for Kids – lots of great projects, low cost materials, easy to follow instructions with pictures, videos
  • Roller Coaster Database and glossary – information about 1000s of roller coasters – Roller Coasters: 6969. Amusement Parks: 3213. Pictures: 50475. Videos: 3131 (as of 9jan2015)
  • Amusement Park Physics – The thrill of roller coasters is not due to their speed, but rather due to their accelerations and to the feelings of weightlessness and weightiness that they produce.