Students build their own small-scale model roller coasters using pipe insulation and marbles, and then analyze them using physics principles learned in the associated lesson. They examine conversions between kinetic and potential energy and frictional effects to design roller coasters that are completely driven by gravity. A class competition using different marbles types to represent different passenger loads determines the most innovative and successful roller coasters.
Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.
All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standard Network (ASN), a project of JES & Co. (www.jesandco.org).
In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.
Click on the standard groupings to explore this hierarchy as it applies to this document.
- Common Core State Standards for Mathematics: Math
- 2. Fluently divide multi-digit numbers using the standard algorithm. (Grade 6)  ...show
- 3. Fluently add, subtract, multiply, and divide multi-digit decimals using the standard algorithm for each operation. (Grade 6)  ...show
- d. Use ratio reasoning to convert measurement units; manipulate and transform units appropriately when multiplying or dividing quantities. (Grade 6)  ...show
- International Technology and Engineering Educators Association: Technology
- E. Design is a creative planning process that leads to useful products and systems. (Grades 6 - 8)  ...show
- G. Requirements for design are made up of criteria and constraints. (Grades 6 - 8)  ...show
- G. Brainstorming is a group problem-solving design process in which each person in the group presents his or her ideas in an open forum. (Grades 6 - 8)  ...show
- J. Make two-dimensional and three-dimensional representations of the designed solution. (Grades 6 - 8)  ...show
- E. Energy is the capacity to do work. (Grades 6 - 8)  ...show
- F. Energy can be used to do work, using many processes. (Grades 6 - 8)  ...show
- I. Much of the energy used in our environment is not used efficiently. (Grades 6 - 8)  ...show
- J. Energy cannot be created nor destroyed; however, it can be converted from one form to another. (Grades 9 - 12)  ...show
- Next Generation Science Standards: Science
- Develop a model to describe that when the arrangement of objects interacting at a distance changes, different amounts of potential energy are stored in the system. (Grades 6 - 8)  ...show
- Construct, use, and present arguments to support the claim that when the motion energy of an object changes, energy is transferred to or from the object. (Grades 6 - 8)  ...show
- Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process such that an optimal design can be achieved. (Grades 6 - 8)  ...show
- North Carolina: Science
- 1.05 Analyze evidence to:
• Explain observations. (Grade 7)  ...show
- 2.03 Evaluate technological designs for:
• Application of scientific principles. (Grade 7)  ...show
- 6.03 Evaluate motion in terms of Newton's Laws: The force of friction retards motion. (Grade 7)  ...show
- 6.05 Describe and measure quantities that characterize moving objects and their interactions within a system:
• Time. (Grade 7)  ...show
- 1.05 Analyze evidence to:
• Explain observations. (Grade 8)  ...show
- 2.03 Evaluate technological designs for:
• Application of scientific principles. (Grade 8)  ...show
- 1.05 Analyze evidence to:
- Explain why it is important for engineers to understand how roller coasters work.
- Explain in physics terms how their model roller coasters work.
- Discuss the effects of gravity and friction in the context of their roller coaster designs.
- Use the principle of conservation of energy to explain the design and layout of roller coasters.
- Identify points in a roller coaster track at which a car has maximum kinetic and potential energy.
- Identify points in a roller coaster track where a car experiences more or less than 1 g-force.
- Identify points in a roller coaster track where a car accelerates and decelerates.
- 2-meter (6 foot) long foam tube (1/2" pipe insulation) cut in half lengthwise (Usually, one side of the tube comes perforated, making it easy to use scissors or a utility knife to cut through the perforation and the other side of the tube to form two halves, essentially making two long channels perfectly shaped to hold marbles; thus, one cut tube provides the track material for two groups; see Figures 1 and 2.)
- glass marble
- wooden marble
- steel marble
- paper or plastic cup
- roll of masking tape
- set of markers, crayons or pencils
- blank sheet of paper
- Roller Coaster Specifications Worksheet, one per student or one per group
- Suggested Scoring Rubric, one per group
- The top of the first hill must be the highest point on the roller coaster.
- Cars move fastest at the bottoms of hills and slowest at the tops of hills.
- Friction converts useful energy into heat and must be minimized.
- G-forces greater than 1 occur at the bottoms of hills.
- G-forces less than 1 occur at the tops of hills.
- To avoid falling, cars must have a certain velocity at the tops of loops.)
|force:||Any push or pull.|
|gravity:||A force that draws any two objects toward one another.|
|speed:||How fast an object moves and is equal to the distance that object travels divided by the time it takes.|
|velocity:||A combination of speed and the direction in which an object travels.|
|critical velocity:||The speed needed at the top of a loop for a car to make it through the loop without falling off the track.|
|acceleration:||How quickly an object speeds up, slows down or changes direction. Is equal to change in velocity divided by time.|
|friction:||A force caused by rubbing between two objects.|
|potential energy:||The energy stored by an object ready to be used. (In this lesson, we use gravitational potential energy, which is directly related to the height of an object and its mass.)|
|kinetic energy:||The energy of an object in motion, which is directly related to its velocity and its mass.|
|gravitational constant:||The acceleration caused by the Earth's gravity at sea level. Is equal to 9.81 m/sec^2 (32.2 ft/sec^2).|
|g-force:||Short for gravitational force. Is equal to the force exerted on an object by the Earth's gravity at sea level.|
Before the Activity
- Gather materials and make copies of the worksheet and scoring rubric.
- Cut each tube in half lengthwise, so each group receives one length of tube that is channel-shaped to serve as the roller coaster track for the marbles (cars). Use scissors or a utility knife to cut through the perforated side of the tube to form two halves. Give each group one of these halves. This process is shown in Figures 1 and 2.
- Review the TeachEngineering lesson, Time for Design, which outlines the steps of the engineering design process. Following these steps while building their roller coasters helps students learn exactly how roller coaster engineers solve problems.
With the Students
- Divide the class into engineering groups of three or four students each.
- Hand out the scoring rubrics for the class competition. The list of creativity points provides students with guidance as to the coaster features (height, turns, loops and corkscrews) that are desired in the design and the list of performance points provides a way to judge the safety of the coasters. Tell the students: In our roller coaster models, the glass marble simulates a normal car, the wooden marble represents an empty car, and a steel marble represents a full car. Your team will earn points for each type of marble (passenger load) that successfully completes your track and lands safely in the cup. A class competition will determine the most innovative and successful roller coasters.
- Have groups start designing their roller coasters, brainstorming and sharing ideas and agreeing on a design. Have students draw their roller coasters on paper, name them, and make signs. Allow up to 30 minutes for this. Look over their drawings to ensure that their proposed designs are physically possible. If not, point out those aspects of the roller coaster design that they may want to rethink. Give them time to iterate their designs.
- Give each group a foam tube track, masking tape and cup, and let them build their roller coasters using classroom materials. Expect students to be able to build their first design in 10 minutes or less. Use the cup to catch the marble at the track end.
- Give students marbles so they are able to test their roller coasters and make any necessary changes. This is the most time-consuming step and students may need up to 45 minutes to redesign their tracks.
- Hand out a stopwatch to each group and give them time to complete the worksheet, in which they determine certain specifications of their roller coasters.
- Start the class competition by telling the students: Similar to what you did today, engineers create small-scale models to help them test and analyze their structural designs. For example, the engineers who designed the Golden Gate Bridge in San Francisco were pioneering new suspension bridge design theory. They verified their complex calculations (all done without computers in the 1930s) of the forces it would need to withstand by performing tests on a steel tower model at 1:56 scale. That's 56 times smaller than one of the actual bridge towers. The tests confirmed that the tower calculations of the anticipated forces, including wind/earthquake deflections, were sound—and the bridge still stands today, more than 75 years later.
- Have each group present its roller coaster model to the class. Use the scoring rubric to evaluate the roller coaster model designs. Discuss the results as a class, as described in the Assessment section.
- Make sure that students do not swallow or throw the marbles.
- Slipping on marbles on the floor could be dangerous. Have students immediately pick up any fallen marbles.
- Make sure that the highest point of the roller coaster is at the beginning.
- Reduce friction by checking that the track is wide enough for the marbles to pass.
- Any track deformation occurring when marbles are rolled down the track results in a loss of energy, so make the roller coaster as stable as possible by taping it to supports (textbooks, walls, desks, chairs, shelves) at several points.
Activity Embedded Assessment
- Which roller coasters were most exciting? Which were safest?
- Which won for creativity? Which won for performance and safety?
- Which model best met the overall challenge for both thrilling design and safety? What were the trade-offs? (Point to make: Engineers call this optimization, balancing competing project requirements.)
- What did you learn from testing your model?
- If you were to redesign your roller coaster, what improvements would you make and why?
- What would happen if you/engineers ignored the fundamental laws of physics in your/their designs?
- How important is it to you that engineers test their designs (for appliances, cars, bridges, stairways, roller coasters, etc.) before they are built and people use them?
- What engineering design steps and techniques did we use today? (Answer: Brainstorming, modeling, simulation, testing, analyzing, redesign, optimization.)
- For lower grade levels, eliminate much of the physics exploration behind the lesson content. Have students build their own roller coasters and discover for themselves many of the concepts that are discussed in detail at higher grade levels (such as energy conservation, friction and gravity), and they may also be capable of understanding some basic explanations of friction and gravity.
- For higher grades, introduce equations for potential and kinetic energy so students can calculate both forms of energy and verify the law of conservation of energy. Have students explore loops along with the concept of critical velocity. Have students find the starting height of a roller coaster necessary to complete a loop of a given height.
History of the Design and Construction of the Bridge: Engineering Design. Posted 2006-2012. Golden Gate Bridge Highway & Transportation District. Accessed November 20, 2013. http://goldengate.org/exhibits/exhibitarea4_2.php
© 2013 by Regents of the University of Colorado; original © 2007 Duke University
Engineering K-PhD Program, Pratt School of Engineering, Duke University
Last modified: March 2, 2015