Students explore the relationship between force and motion and the effects of weight and lift on a glider. Students learn the relationships between data analysis and variable manipulations, and the importance of understanding consumer demands. The glider activity culminates in a book-signing event where each design team presents its prototype and the class presents its manuscripts to Mobility Press "representatives" and members of the local community.

The Glider Challenge has been designed to supplement the curriculum of teachers and is intended for eighth-grade students whose teachers are using a multidisciplinary approach. Like all AWIM challenges, the Glider Challenge will join together teachers, students, and industry volunteers in an exploration of physical science while addressing essential mathematic and scientific concepts and skills.

In the Glider Challenge a fictitious publishing company called Mobility Press contacts the students in a letter which explains that it wants to publish a book of designs for gliding toys that children of ages 8-12 can build with assistance from an adult. The company invites the class to submit a manuscript that includes drawings and plans for building the gliders, as well as instructions for how to fly them and a description of how they work. Student design teams design two products: a gliding toy and a set of book pages that describe how to build and fly the toy. Over the course of the eight weeks, a variety of activities prepare the students to develop a prototype gliding toy and a book manuscript. The challenge culminates in a book-signing event, in which the class presents its book and student design teams present their gliding-toy prototypes.

**Resources:**

**Lesson 1: Receiving the Letter from Mobility Press (45 min)**—Students receive a letter from Mobility Press (a fictitious publishing company) that sets the context for the challenge. Students read the letter, and are introduced to the engineering design experience and the scope of the design task with which they will be engaged in the unit.

The letter from Mobility Press says that it is interested in publishing a book of designs for gliding toys that children ages of 8-12 can build with assistance from an adult. The publisher is asking students to act as toy designers and to submit a manuscript for the book, which will include drawings and written plans for building the gliders, as well as instructions for how to fly them, and a description of how they work. Students will work in design teams to design two products: a gliding toy and a set of book pages for the manuscript that describe how to build and fly the toy.

**Lesson 2: Seeing the Big Picture (45 min)**—Design teams determine how to respond to the challenge presented in the letter from Mobility Press. Students use their understanding of the letter to answer several questions about what the basic requirements of the challenge from Mobility Press are. They define specific tasks they will need to accomplish to meet the design challenge successfully.

**Lesson 3: Forming Design Teams (45-90 min)**—Students are divided into design teams. The class discusses how to work in teams, the importance of working in design teams, and the roles individuals will take in their teams. The teams identify and collect examples from magazines of company logos and slogans. They discuss how companies use logos and slogans to appeal to customers. Students then work in their design teams to produce a team name, logo, and slogan.

**Lesson 4: Meeting an Engineer (45 min)**—Students meet a volunteer engineer who talks to them about how engineers work when they design things. The volunteer's conversation with the students focuses on the engineering design experience, especially two important aspects of the design process that students will encounter: working in design teams and using design logs to keep careful records of their work. Students can ask the engineer the questions they have prepared as homework.

**Lesson 5: Using Design Logs (45 min)**—In this unit, student design teams will record their work in Design Logs. This activity introduces students to the important reasons for keeping a Design Log and ways they can use their Design Logs to keep a record of their design work and reflect on their designs. Students also learn how the teacher will use the Design Logs for assessment.

**Lesson 6: What We Know About Flight (45 min)**—Students make a list of the variety of things that fly. They discuss the characteristics of different kinds of flying objects. They then consider gliding objects as a special kind of flying object, make a list of gliding objects, and identify their attributes. Students create a working definition of "gliding" to use in the development of gliding toys for Mobility Press.

**Lesson 7: Groundwork in Statistics and Graphs (45-90 min)**—Students complete a short survey and review measures of central tendency (range, median, mean, mode) by analyzing the data they collect. They compare and calculate percentages of data presented in cross-tabulations and construct graphs that show data as frequency counts or percents.

**Lesson 8: Targeting the Young Consumer (90 min)**—Students learn about marketing strategies and how companies collect and analyze consumer data to learn about their customers. Students read and interpret the first part of a report from a market research group. This part of the report describes the purchasing characteristics and behaviors of consumers from infancy to young adulthood. Students use the information in the report to begin to define their target market.

**Lesson 9: Narrowing the Target (90 min)**—Students add to and summarize their knowledge about the consumers they are targeting by reading the rest of the America's Young Consumers Market Research Report. Using tables and graphs based on a set of real data, students draw conclusions about children's experiences with flying toys and with books that show how to make things. Based on what they find, each design team selects a subgroup of children to be their target market. They summarize in writing what they have learned and how they will apply their new knowledge to their design.

**Lesson 10: More Market Research (90 min)**—Students design and carry out their own market research. To find out more about their target customers, they develop questions for a focus group, interview, or survey and gather data. They make their own tables and graphs to organize and display their data. After analyzing the results of their research, they decide how they will use the new information they have acquired.

**Lesson 11: Making Preliminary Models (90 min)**—In this activity students design, build, and test a gliding model. Each student design team first plans what its gliding toy will look like. Team members make and share sketches, then decide on a design and make a final sketch. They draw the outlines of each part on a sheet of foam, cut out the pieces of their model, and assemble it using rubber bands and tape. Design teams then test their models and make adjustments and revisions as they see fit.

**Lesson 12: Sharing Preliminary Models (45 min)**—Each design team demonstrates its preliminary model for the class. The class then makes observations about which characteristics seem to help or hinder the flight of their models.

**Lesson 13: Revising Preliminary Models (45-90 min)**—Students redesign their preliminary models based on their own understanding as well as on discussion and feedback from the class from the previous activity. This activity introduces students to design as an iterative process. After building and testing their redesigned models, students present their revised designs and share test results, observations, problems, and solutions with the class.

**Lesson 14: Introducing the Standard Model (90 min)**—In the next several activities, each design team works with the "Standard Model." The standard model enables students to examine the effects of adjusting the positions of the wings, the stabilizer assembly, and adding weight to the model. In this activity, students become acquainted with the Standard Model. They invent their own ways to arrange the balsa fuselage stick, the wing, and the stabilizer assembly (see illustration on page 6). They test fly the Standard Model in these different configurations, observe its flight path, and discover that some configurations result in better flights than others. Each design team shares its findings with the class.

**Lesson 15: Designing Experiments (45-90 min)**—In this activity, students plan a series of systematic experiments on the Standard Model that they will carry out in later activities. Students investigate the need to test one variable at a time while holding the other variables constant. They also learn a method for recording the results of their flight tests.

**Lesson 16: Interpreting Experimental Data (90 min)**—Students use basic statistics to interpret a series of flight test results. They use this data to create a graph showing the relationship between weight and flight distance (with wing position, launch stretch and all other variables held constant). To accomplish this, students use the following five-step process:

- Assess the data to decide which data to include and which to exclude (if any).
- Find average values of flight distance for each value tested.
- Make a graph of average flight distance vs. value tested.
- Look for patterns in the graph, especially patterns that help identify the test value or values that resulted in the longest flight.
- Make predictions for other test values that might give even better results.

**Lesson 17: Varying the Nose Weight (90 min)**—In the next several activities, students use the experimental method to understand how changing a single variable affects the flight of the standard model. In this activity they test the single variable of nose weight, holding other relevant variables constant. They analyze their data using the same procedure they used with the prepared data set in the Interpreting Experimental Data activity. Students also are introduced to force diagrams, which they use to think about the forces acting on the model as it flies.

**Lesson 18: Optimizing Wing Positions for Different Nose Weights (90 min)**—Each team of students tests a glider with a different nose weight, systematically varying the wing position to find the one that gives the longest flight. First they obtain preliminary data by testing a series of different wing positions to find the one that results in the longest flight. Then they test other wing positions, including those that are slightly before and slightly behind the best wing position from the preliminary test flights. Each team continues to vary the wing position slightly until members are convinced they have found the one that gives the longest flight for their given nose weight. Results from all the teams' experiments are compared to determine how the optimal wing position changes for different nose weights.

**Lesson 19: Investigating Force, Balance, and Center of Gravity (90 min)**—Students are introduced to the concepts of balance and center of gravity as factors to consider in flying their gliders. This activity includes a teacher-led demonstration, some simple guided experiments, and a good deal of discussion. Students first consider the balance of forces on a static glider as it is held in the air, as well as the unbalanced forces when the glider is falling. Then they use a simple pin and string to find the point at which a Standard Model balances without tipping forward or backward, and interpret three force diagrams showing the upward and downward forces when the glider is balanced and unbalanced. They make and test predictions about what will happen if the pin is moved or if the glider's nose weight is changed. Finally, students consider the significance of a glider's center of gravity on its flight path. They use force diagrams to predict what will happen with the wing behind, in front of, and directly over the glider's center of gravity. They use their results from the Optimizing the Wing Position for Different Nose Weights activity to verify their predictions and find the center of gravity for the nose weight and wing position that gave their glider its longest flight. They compare results from each team to show that in each case the balance point is under the glider's wing, and that gliders with greater nose weight have their centers of gravity closer to the nose.

**Lesson 20: Graphing the Center of Gravity vs. Nose Weight and Wing Position (45-90 min)**—Students carry out two mathematical experiments, plot the results on a graph, discuss the forms of the graphs, and make predictions based on the graphs. First, they find the position of the glider's center of gravity for different values of nose weight. They examine the data to determine whether there are predictable relationships between the two. Results should show an inverse relationship between these variables. That is (with wing position constant), increasing weight decreases the distance of the center of gravity from the nose of the plane. Conversely, decreasing weight increases the distance to the center of gravity.

Second, they find the position of the glider's center of gravity as the wing position is changed, while nose weight is held constant. Results for this should show a linear relationship. As the distance of the wing from the nose increases, the distance from the nose to the center of gravity increases proportionally.

**Lesson 21: Varying the Launcher Stretch (90 min)**—Design teams perform experiments to investigate how varying the amount of stretch in the launcher's rubber band affects the flight path and distance of the model. As in previous activities, students graph their data in order to look for patterns and make predictions for optimal launcher-stretch values.

**Lesson 22: Wings with Different Mathematical Properties (optional) (45 min)**—Students determine and compare the mathematical properties of different wing shapes: area, mean chord length, and aspect ratio.

First, students calculate the area of each sample wing in one of three ways:

- Using standard formulas for rectangular and triangular wings;
- Combining rectangles and triangles to find the areas of other shapes when possible;
- Counting squares on graph paper when neither of the above methods work.

Next, students calculate the mean (average) chord length for each wing. The chord is the distance across the wing from front to back. The mean chord length for a non-rectangular wing is equal to the chord of a rectangular wing with the same area and span. Therefore, once students know the area of a wing, they can easily find the chord for a rectangular wing with the same area and wing span. They do this by dividing the wing's area by its wing span. Finally, students determine the aspect ratio for each wing, that is, the wing span divided by the mean chord length.

**Lesson 23: Testing Wing Properties (optional) (45-90 min)**—Students discuss how they think different wing properties, such as area, span, chord, aspect ratio, and shape might affect the flight path of the Standard Model. Design teams choose a wing property to investigate that they think will give them information about the type of wing they are considering designing for their gliding toy. Students design and carry out experiments that they think will give them useful data on the wing properties they have chosen. Design teams then share their findings with the class.

**Lesson 24: Designing a Page Layout (45-90 min)**—Students learn about fundamental elements or concepts in designing text— and specifically instructions—on a page, including how to create good proportion and balance. They begin to understand these concepts by examining various examples of page design. Students also learn terms used in page design, such as typeface (or font or display type), grid, margins, and white space.

**Lesson 25: What We Know About the Standard Model (45-90 min)**—Students summarize their findings about the Standard Model from the testing they have done. The class discusses the effects of the tested variables on the flight path and the distance flown. Instead of trying to find optimal values, students consider how to adjust values to change the flight path of a model prepared and demonstrated by the teacher. Students discuss the interrelationship of the variables. They discuss the observation that there is no optimum setting for any single variable. The effect of each setting depends on all the other settings. Students fill out a sheet that depicts the forces that act on the Standard Model as it flies, and discuss the relationship of the forces and the flight path of the Standard Model.

**Lesson 26: Receiving the Requirements from Mobility Press (45 min)**—Students receive a letter from Mobility Press that gives them detailed information about the design requirements for both the gliding toy and the book pages. Students read the letter, answer questions about it, and begin to plan their response.

**Lesson 27: Integrating and Applying What We Know (45-90 min)**—In this activity, students begin to integrate and apply their understanding gained in the Set Goals and Build Knowledge phases to a successful toy glider design. Design teams begin to reconcile the specifications required by Mobility Press as described in its letter, their understanding of the factors involved in the performance of gliders, and their understanding of the needs of the consumers they have investigated.

**Lesson 28: Writing a Design Brief (45 min)**—In this activity, student design teams use the information from their analysis in the Integrating and Applying What We Know activity to write a design brief, which is a brief description of the product. The Design Brief specifies the characteristics of the gliding toy they plan to design for the book for Mobility Press. The Design Brief includes the appearance of the gliding toy and the kind of gliding performance the toy is designed to have.

**Lesson 29: Making a Design Drawing (45-90 min)**—Design teams produce drawings of their toy designs based on the Design Brief they wrote in the Writing a Design Brief activity.

**Lesson 30: Building a Prototype (45-90 min)**—Design teams build a prototype based on the design drawings they made in the Making a Design Drawing activity.

**Lesson 31: Testing, Evaluating, and Adjusting the Prototype (45-90 min)**—Design teams test their prototypes to see if their designs meet the performance criteria they specified in their Design Briefs. They use their understanding of the factors that affect the flight path to troubleshoot and improve their designs. Each team makes adjustments to its model to help make its flight path correspond as closely as possible to that specified in the team's Design Brief. These may include moving the wings or other flight surfaces and changing the weight on the nose of the model. They repeat the testing, evaluating, and adjusting process until the model meets their performance specifications, or they decide that adjustments are not enough to get the flight path they want, and they must redesign it.

**Lesson 32: Quality Assurance Testing (45 min)**—Students discuss the requirements of Mobility Press for reliability in the performance of their gliding toys. They discuss the need for quality assurance in industry and the corresponding need to test their prototypes to see that they meet their own performance standards. The class decides on a testing procedure that they think will convince Mobility Press that their prototypes are reliable. Design teams pair up with a testing-partner design team and test one another's prototypes. Students use a test sheet like those they used in the Standard Model experiments to record test data.

**Lesson 33: Planning the Book Content (45-90 min)**—The class makes initial plans for the organization of the book of gliding toy designs it will create. Students list and discuss the requirements for the book given in the Mobility Press Requirements Letter. They discuss ways to prepare an introduction, a glossary, and a table of contents. They begin thinking about ideas for a title and a book cover design. Finally, students consider whether or not to organize the gliding toy design entries in groups.

**Lesson 34: Planning the Book Production (45-90 min)**—In this activity, students make decisions about how to transform their written design entries into an actual "published" book. Students discuss who will receive a copy of the book, who will pay for the paper and duplication, the number of copies to make (the print run), and how to print, assemble, and bind the finished copies.

**Lesson 35: Organizing the Design Entries (45-90 min)**—Students examine examples of published design instructions as an introduction to learning how to write clear, easy-to-follow instructions for their own design entries. They examine factors that affect how this kind of information is communicated and assess the effectiveness of these factors. They make initial decisions about how to organize their design entries.

**Lesson 36: Writing Instructions for Building and Flying (45-90 min)**—Design teams write instructions that show readers how to build and fly the gliding toys designed by students. Each team must consider how to integrate text and graphics in order to convey the assembly process clearly to its target audience. Students also write explanations of the features that cause their gliding toy to demonstrate its particular flight path.

**Lesson 37: Making Scale Drawings (90 min)**—Design teams make reduced-scale drawings of the wing surfaces of their gliding toys for incorporation into their design entries, as part of the instruction for building the gliding toys. The drawings are intended to be enlarged and then cut out with scissors by the readers of the book.

**Lesson 38: Sharing Final Designs (90 min)**—In this activity, student design teams share their final gliding toy designs with the class. Teams will present their design brief specifications, design drawings, consumer data, and flight test results. Each team launches its model to show how well it meets their design brief specifications. The class discusses the relationship between the design of the models and their performance. Students then reflect on how their understanding of gliding toys has grown since they began the challenge.

**Lesson 39: The Book-Signing Event (90 min)**—The culminating event—a book signing—is a celebration and an opportunity for students to show off their gliding toys and their book of designs. Design teams demonstrate their finished designs and sign copies of the book for one another as well as for invited guests. Each design team may also set up a "poster session" station and give a short presentation about its contribution to the book, demonstrate its gliding toy, and autograph the book. Other formats might be considered, perhaps after you talk with publishers and book stores about such events.

**Lesson 40: Reflecting on the Engineering Design Experience (45 min)**—Students discuss the experiences they have had in the unit. They reflect on the work they did in each of the phases of the engineering design experience. They discuss what the engineering design experience is.