Transcript Roller Coasters: How They Work

ROLLER COASTERS:
THE PHYSICS BEHIND THE THRILL
By Marianna Garlisi &
Felicia Giambalvo
HOW DO ROLLER COASTERS WORK?
A roller coaster ride is a thrilling experience that involves several components of
physics.
The Ascent
As a roller coaster leaves the boarding station, a
chain and motor exerts force on the train of cars to
lift them to the top of the first hill. The purpose of
the coaster’s initial ascent is to build up potential
energy.
This is explained by the equation for potential energy: Ug=mgh
where Ug is potential energy, m is mass, g is acceleration due to gravity, and h is
height above the ground.
HOW DO ROLLER COASTERS WORK? (CONT.)
At the Peak
At the top of the first hill, the potential energy is at its maximum
because this is the highest the train of cars will ever get.
The train of cars are released from this height, at which point it
will roll freely along the track without any external mechanical
assistance.
The Law of Conservation of Energy states that energy can neither be created nor
destroyed, thus, the purpose of the ascent of the first hill is to build up potential
energy that will then be converted to kinetic energy as the ride progresses.
Kinetic energy is the energy of motion.
HOW DO ROLLER COASTERS WORK? (CONT.)
The Descent
As the train of cars begins its descent, gravity takes over and the stored potential
energy converts to kinetic energy.
Kinetic energy quantifies the amount of work the object could do as a result of its
motion. The total mechanical energy of an object is the sum of its kinetic energy and
potential energy.
The further the train of cars drops, the more potential energy gets converted to kinetic
energy. In other words, the train of cars picks up speed as it falls.
At the bottom of the hill, there is maximum kinetic energy and little potential energy.
HOW DO ROLLER COASTERS WORK? (CONT.)
The Ascent Up the Second Hill
In theory, the train of cars at the bottom of the first drop should have enough energy
to get back up to the height of the first hill. Yet, dissipative forces, such as friction and
air resistance, causes the energy to be converted into heat energy. Heat energy does
not propel the roller coaster ride in any way.
As the train of cars begin its ascent up the second hill, the
kinetic energy obtained from the bottom of the hill is
converted back into potential energy, decreasing the roller
coaster ride’s velocity.
HOW DO ROLLER COASTERS WORK? (CONT.)
Coming to a Stop
The process of converting kinetic energy to potential energy and
back to kinetic energy continues with each hill of the ride.
As the tracks direct the ride through various hills, slopes, and
angles, energy is gradually lost and converted to heat energy.
Although the train of cars has slowed down, brakes at the end of the ride bring the
train of cars to a complete stop.
Then, the process begins all over again as the next group of people are sent up the
first hill.
DISCUSSION
Prior to completing this project, we believed roller coasters not only relied on
components of physics, but were also propelled by a motor. We came to the
realization that a lot more engineering goes into making rides than we had originally
thought. It was not until now that we realized the importance of physics in creating a
safe and enjoyable ride. Roller coaster designers must calculate several components
of physics to create a ride that feels dangerous, but in reality is quite safe.
BIBLIOGRAPHY
Harris, Tom. (2007). How Roller Coasters Work. Retrieved from
http://science.howstuffworks.com/engineering/structural/roller-coaster3.htm.
Pescovitz, David. (2007). Roller Coasters. In Encyclopedia Britannica online. Retrieved
from http://search.eb.com/coasters/ride.html.
Sandborg, David. (1996). Physics of Roller Coasters. Coaster Enthusiasts of Canada.
Retrieved from http://www.chebucto.ns.ca/~ak621/CEC/Co-Phys.html.