Roller Coaster
For many people, there is only one reason to go to an amusement park: the roller coaster. Some people call
it the "scream machine," with good reason. The history of this ride reflects a constant search for greater and
more death-defying thrills.
How does a roller coaster work?
What you may not realize as you're cruising down the track at 60 miles an hour is that the coaster has no
engine. The car is pulled to the top of the first hill at the beginning of the ride, but after that the coaster
must complete the ride on its own. You aren't being propelled around the track by a motor or pulled by a
hitch. The conversion of potential energy to kinetic energy is what drives the roller coaster, and all of the
kinetic energy you need for the ride is present once the coaster descends the first hill.
Once you're underway, different types of wheels help keep the ride smooth. Running wheels guide the
coaster on the track. Friction wheels control lateral motion (movement to either side of the track). A final
set of wheels keeps the coaster on the track even if it's inverted. Compressed air brakes stop the car as the
ride ends.
Potential versus Kinetic Energy
Potential energy is energy that is stored in an object. If you stretch a rubber band, you will give it potential
energy. As the rubber band is released, potential energy is changed to motion.
Kinetic energy is energy of motion. A rubber band flying through the air has kinetic energy. When you are
walking or running your body is exhibiting kinetic energy. Potential energy is converted into kinetic
energy. Before the roller coaster begins the downward ride it has stored energy due to its position. At the
top it has its maximum potential energy. As it starts to fall the potential energy begins to be changed into
kinetic energy. At the bottom its potential energy has been changed into kinetic energy so that it now has its
maximum kinetic energy. A waterfall has both potential and kinetic energy. The water at the top has
stored potential energy. When the water begins to fall, its potential energy is changed into kinetic
energy.
Wooden or steel coaster: Does it make a difference?
Roller coasters can be wooden or steel, and can be looping or nonlooping. You'll notice a big difference in
the ride depending on the type of material used. In general, wooden coasters are nonlooping. They're also
not as tall and not as fast, and they don't feature very steep hills or as long a track as steel ones do. Wooden
coasters do offer one advantage over steel coasters, assuming you're looking for palm-sweating thrills: they
sway a lot more. Tubular steel coasters allow more looping, higher and steeper hills, greater drops and rolls,
and faster speeds.
Roller Coaster History
In the 1600s in Russia, the forerunners of present-day roller coasters were huge blocks of ice that were
fashioned into sleds, with straw or fur on the icy seat for passenger comfort. Sand was used to help slow
down the sled at the end of the ride to keep it from crashing, a technique based on the principle of friction.
Later, more elaborate wooden sleds were built with iron runners to increase the speed and intensity of the
ride.
The first American coasters
America's amusement park history begins on Coney Island in 1875. Railway companies, in search of ways
to keep passenger usage up on the weekends, set up parks here at the end of the rail lines and introduced
weekend and summer activities. The first rides at these parks were carousels, but in 1884, the first gravity
switchback train was introduced. This was the first true roller coaster in America.
In 1912, the first under-friction roller coaster was introduced by John Miller. This design held the coaster
train on the track and allowed for more speed, steeper hills, and less drag. The 1920s saw the building of
some of the best roller coasters of all times. But the 1929 stock market crash, followed by the Great
Depression and the Second World War, caused a decline in the parks.
A new era for roller coaster design
In 1955, the nation's first theme park opened: Disneyland. Not only did Disneyland usher in a new era for
amusement parks, it also helped bring about some radical changes in roller coaster design. Up until this
time, coasters were built out of wood, which limited the way loops could be handled. In 1959 Disney
introduced the Matterhorn, the first tubular steel coaster. The exciting features we expect from today's
coasters--loops, a corkscrew track, and stability--can be traced back to this first steel coaster.
The first successful inverted coaster was introduced in 1992, and now you can find passengers riding in
coasters with their feet dangling freely below them (and occasionally above them) as they circumnavigate
the track. In 1997, a coaster opened at Six Flags Magic Mountain whose design would have been
considered impossible even a few years before. This scream machine is 415 feet tall and can reach a speed
of 100 miles per hour. Technology, working with the laws of physics, continues to push what is possible in
ride design.
"Amusement Park Physics" is inspired by programs from The Mechanical Universe...and Beyond. © Annenberg Foundation 2011.
Analysis Questions: Please write complete sentences on a separate piece of paper.
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How does a roller coaster work if it does not have an engine?
What types of wheels help to control the roller coaster? Explain the different types and the
purpose of each type of wheel.
What is the difference between potential and kinetic energy?
Give at least two examples of potential energy.
Give at least two examples of kinetic energy.
Think of an example or potential and kinetic energy that is not in the reading. Please name your
example and explain when potential energy exists and when kinetic energy exists.
When does a roller coaster have maximum (the most) potential energy? This answer should be a
location on the track.
When does a roller coaster have maximum (the most) kinetic energy? This answer should be a
location on the track.
Make a drawing of a roller coaster and label where it would have maximum potential energy and
where it would have maximum kinetic energy.
What is energy? Try to come up with a definition on your own.
What are some differences between wooden and metal roller coasters?
Where did the first roller coasters exist? What were they made out of?
Where was the first true roller coaster in America?
Name some other historical moments for roller coasters.
Make a list of difficult words from the article.
Name: ________________________________ Date: _________________ Period: __________
Analysis Questions: Please write complete sentences on a separate piece of paper.
1. How does a roller coaster work if it does not have an engine?
2. What types of wheels help to control the roller coaster? Explain the different types and
the purpose of each type of wheel.
3. What is the difference between potential and kinetic energy?
4. Give at least two examples of potential energy.
5. Give at least two examples of kinetic energy.
6. Think of an example or potential and kinetic energy that is not in the reading. Please
name your example and explain when potential energy exists and when kinetic energy
exists.
7. When does a roller coaster have maximum (the most) potential energy? This answer
should be a location on the track.
8. When does a roller coaster have maximum (the most) kinetic energy? This answer
should be a location on the track.
9. Make a drawing of a roller coaster and label where it would have maximum potential
energy and where it would have maximum kinetic energy.
10. What is energy? Try to come up with a definition on your own.
11. What are some differences between wooden and metal roller coasters?
12. Where did the first roller coasters exist? What were they made out of?
13. Where was the first true roller coaster in America?
14. Name some other historical moments for roller coasters.
15. Make a list of difficult words from the article.
Roller Coaster Energy Conversions: Complete the following problems.
HT= 250m
WT= 200 N
HT= 20m
WT= 200 N
M= 20kg
V= 70 m/s
Above is a picture of a typical roller coaster. In each of the 3 boxes, describe the
types of energy present. Use the following descriptors (one for KE and one for PE in
each box):
Low KE
High KE
Maximum KE
Low PE
Minimum PE
Maximum PE
Then, describe the series of energy conversions on this roller coaster in the box below
the picture. You are creating the caption for the picture, so be sure to write in a good
paragraph.
Problems: Show your WORK, include the formulas used and correct units.
1. Find the PE at point A.
2. Find the KE at point A.
3. Find the ME at point A.
4. Find the KE at point B.
5. What is the ME at point C?
6. Find the PE at point C.
7. Find the KE at point C.