June 13, 2017

Kacey Templin

The Science of Roller Coasters

Topics: STEM Education / Play, STEM


School is out and summertime is upon us, which means that amusement park season is in full swing. Children and adults alike look forward to playing carnival games, eating popcorn and funnel cakes, and of course, riding roller coasters. Coasters have been an anchor for American amusement parks for decades, drawing in thrill seekers from around the globe. Guests willingly wait hours in line for a few minutes of thrill, a chance to experience that adrenaline high that makes us giddy. Not everyone enjoys roller coasters, but most find them fascinating. They’re thrilling, chilling, and an excellent study in the power of physics.

Roller Coasters: A History

The earliest roller coasters were inspired by ice slides constructed in 18th-century Russia. These so-called “Russian Mountains” were located in palaces around St. Petersburg, and quickly became popular attractions for the upper class. The first true roller coaster was opened in Parc Beaujon in Paris on July 8th, 1817, but the first modern roller coaster, what we might recognize today, was the Switchback Railway. Constructed in 1884 at New York’s Coney Island, the ride was modeled partly on the coal-mining trains in Pennsylvania and travelled at a mere 6 miles per hour.

It didn’t take long for the U.S. to catch roller coaster fever, and soon amusement rides were popping up across the country. Designers began to test the limits of coaster dynamics, occasionally making rides that were too dangerous. Olentangy Park’s Loop the Loop and the Flip Flap Railway at Sea Lion Park were dismantled shortly after being built in 1895 due to passengers suffering from whiplash. All early roller coasters were made of wood, and it wasn’t until the 50’s that steel roller coasters were created. This was a true breakthrough, because steel could be bent in any direction, allowing designers to incorporate loops, corkscrews, and many other new thrills. Coasters today are built using the newest technologies and designs to maximize what riders experience.

The Thrill


Why do some people enjoy the adrenaline rush associated with these daredevil rides? It comes down to the rush you feel when you experience the fear of losing control. Once a roller coaster starts, there’s nothing a passenger can do. Humans have not changed much since we were hunter-gatherers, but our world has changed dramatically. Today, we live lives that are relatively tame compared to a few thousand years ago. Some people still feel the drive to experience thrills, and want to do so in a safe environment. Roller coasters allow us to tap into our primal need for the adrenaline rush humans once felt on a more frequent basis.

To enhance the thrill, park engineers employ psychological deception, incorporating ride elements that are guaranteed to scare. When riding a wooden roller coaster, you might notice the ride creating lots of noise, like it may collapse at any second. Some coasters have dark tunnels to disorient riders. Beams placed low enough so that it appears to whiz right past your head are expertly placed. “We try to make [roller coasters] look and feel more dangerous than they really are,” says Michael Boodley, former president of Great Coasters International, a wooden roller coaster manufacturer. All of this is designed so that you can experience the greatest rush.

The Science

Look at a modern roller coaster and you might think they’re created by madmen. While some may be a little crazy, coaster engineers must have a good, clear grasp of physics concepts to create those thrilling rides. To make the cars zip around the track, engineers must create potential energy. Potential energy is created from the combination of mass, gravity, and height. Ever notice how many roller coasters start out with a tall hill? This is meant to build as much potential energy as possible. It’s like stretching a rubber band as far as you can. The farther you stretch it, the farther it will fly when you let it go. Once your coaster gets over the hill, it then starts to gain kinetic energy. This is the type of energy that helps to push you through whatever twists and turns come next.

A product of this acceleration is the all-important G-force. We live in an environment of 1 G, which is equal to the force of gravity on Earth’s surface. You can change the effect of G-force on your body if you accelerate away from or towards Earth’s pull on your body (i.e. that force that keeps our feet on the ground). So, once you’ve crested that first large hill and start accelerating downwards, you may begin to lift up out of your seat. That’s negative G-forces. Then, when you pull out of the lowest dip, you feel yourself sinking back into the seat from the positive G-forces. You can also feel lateral G-forces when you make horizontal turns. Because of this, designers make curves banked so that you aren’t thrown against the side of the car while making a turn.


As you take on the loop-de-loops you may wonder why you aren’t falling out of your seat at the height of the loop. This is, in part, due to inertia. Inertia is what keeps an object moving in a straight line, a constant state of uniform motion. When an external force (such as gravity) is applied, this causes a loss of inertia. Inertia combined with the increased gravity in the loop pushes you into your seat and keeps you safe on those hair-raising turns. 

G-force is a huge factor in designing roller coasters. Too much force, or too swift a transition between positive and negative G can be dangerous. Modern rides are being built to be bigger, badder, and faster than anything before, but interestingly (and thankfully), they still maintain the same G-force levels. While designers look for the biggest thrill factor, engineers must consider the physics of the ride, making roller coasters a product of both science and art.

Roller coasters capture the imagination of the young and the old alike. They are a testament to the creativity and innovation within us. If you have plans to visit an amusement park this summer, take a moment to spot the amazing physics concepts built into the rides. And if you don’t have any plans to visit, you can always try out these concepts by building a roller coaster in the comfort of your home!