Hands-on Activity Sled Hockey Design Challenge

Learning Objectives

After this activity, students should be able to:

• Apply geometric methods to solve design problems.
• Test tension and flexure on designed materials.
• Identify forces and their role in testing.
• Implement the engineering design process throughout this activity.

Educational Standards

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 Standards Network (ASN), a project of D2L (www.achievementstandards.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.

NGSS: Next Generation Science Standards - Science

Common Core State Standards - Math

International Technology and Engineering Educators Association - Technology

State Standards

Materials List

Each group needs:

• cell phone or digital camera for research and picture documentation
• lab notebook or journal
• ruler
• meter stick
• graph paper, 1 sheet
• roll of masking tape
• 75 tickets from a roll of tickets (similar to this one at Amazon)
• poster board
• 10 sheets of printer paper
• 20 drinking straws
• 30 pipe cleaners
• 0.75 m x 0.5 m (~20 in x 30 in) foam board
• 0.75 m x 0.5 m (~20 in x 30 in) cardboard
• scissors or X-Acto® knife
• copies of Pre/Post-Quiz, Forces, Scatterplots, and Polygons Worksheet, Student Log Book, Engineering Design Process Handout, Enginering Design Process Rubric, and Testing Procedures Sheet
• duct tape

To share with the entire class:

• set of weights; 0.5 kg to 5 kg (~1 lb to ~10 lb) increasing in 0.5-lb increments. See Troubleshooting Tips for notes on weights.

Worksheets and Attachments

Introduction/Motivation

What comes to mind when you think of a materials engineer? (Allow students to think specifically about the word “materials” and welcome any suggestions.) Materials engineering is a field that studies, discovers, and designs the properties of structures of existing materials in order to create new materials. One example of what a materials engineer might do is assist an architecture firm that with designs for an environmentally-friendly building. The firm may hire an engineer to develop a sustainable insulation out of previous iterations of insulation by adding to the material. In aerospace engineering, materials engineers are often tasked with designing components for use in aircraft that are lighter, stronger, and can carry heavier loads. Materials engineering, however, is not just limited to large industries. Think about what athletes wear or use for equipment. Uniforms made today are far lighter, more breathable, and more flexible that what was available thirty or forty years ago, and part of this evolution is due to advances in textiles, plastics, and carbon-based materials that were all developed by an engineer. In a way, engineering has also helped democratize sports by introducing designs that can help individuals with physical disabilities compete. In this activity, we are going to explore the engineering behind one such innovation used in sled hockey: the sled hockey stick!

Sled hockey was invented when individuals wanted to continue to play hockey despite their physical limitations. Along with designing a sled with skate blades instead of the usual rails, they developed “sticks” that were made of bicycle handles. As the sport grew, players wanted their sticks to mimic what ice hockey sticks look like. However, these sticks needed to be exceptionally strong. Not only are the sticks used to pass the puck, they are also used to propel a player on the ice— a motion that uses a tremendous amount of upper-body strength.

Now, to discuss your task: this class will help a new sports team develop its equipment. This sled hockey team will need new sticks that can withstand lots of game-to-game wear and tear. Sled hockey sticks are 52 cm (20.5 in) long, 1.9 cm (0.75 in) wide, and 3.2 cm (1.25 inches) tall. Part of your design challenge is to use polygons in the stick to create more support. Along with your design, and materials that include tickets, masking tape, poster board, printer paper, straws, pipe cleaners, foam board, and cardboard, you will construct a replica of a hockey stick. To test its strength, you will put the stick through flexure (bending) testing.

Procedure

Background

How do you design a sled hockey stick? For starters, student engineers should be mindful of the forces exerted on a stick during play. Sled hockey is as intense a sport as ice hockey! Materials engineers may evaluate a range of different materials such as wood and composite carbon fiber for their strength and ability to flex. During flexure testing, they add weight to the middle of the hockey stick while keeping the ends stable and then measure the stick’s flexibility. They add more and more weight to determine the maximum amount of force a stick can withstand before breaking.

Another key concept is force, specifically the push or pull on an object. In mathematical terms, force is related to product of acceleration (usually by gravity, g=9.8 m/s²) and the mass of the object using the equation F=ma. F is the force in Newtons (N), m is the mass in kilograms (kg), and a is the acceleration in meters per second squared (m/s²). An overview of normal and tension forces is provided in the Forces, Scatterplots, and Polygons Worksheet.

In this activity, students work through the engineering design process as outlined in the Engineering Design Process Handout, which guides them through the seven steps to create a prototype hockey stick.

Before the Activity

• Make enough copies of the Pre/Post-Quiz, Forces, Scatterplots, and Polygons Worksheet, Engineering Design Process Handout, Student Log Book, one for each student to have one. Determine how many groups you will have based on specific class sizes.
• Make enough copies of the Testing Procedures Sheet, one per group.
• Distribute project materials for students to use (Day 3).  

With the Students

Day 1

1. Introduce the project to the students.
1. The school wants to create a hockey stick for a new sled team and this class has been asked to help with the project. Students will create one prototype sled hockey stick. The sticks should be 52 cm (20.5 in) long, 1.9 cm (0.75 in) wide, and 3.2 cm (1.25 inches) tall. By assessing the flexural distance during the testing procedure, you will then redesign and construct a new stick that adjusts any failures that were present in the initial testing.
2. Show the video (2:34 minute long): https://www.youtube.com/watch?v=9gsy9Som_xs
3. Show the video (4:16 minute long): https://www.youtube.com/watch?v=J57TP5TrNwg
2. Instruct students to complete the Pre/Post-Quiz.
3. Instruct students to complete “Day 1” questions in the Student Log Book.
4. Look over student answers. Highlight any questions that may have been particularly difficult for the group as a whole.

Day 2

1. Split the class into groups (these groups can be chosen by the students or assigned). There should be about four students in each group. 
2. Review the Forces, Scatterplots, and Polygons Worksheet as a class.  

1. A normal force exists between two solid objects when their surfaces are pressed together due to other forces acting on one or both sides. 
2. If an object is sitting on a table or level surface, then the normal force is opposite and equal of the weight of the object. 
3. A tension force occurs using, for example, a rope that pulls another object. Picture an elevator hanging from a wires that pull it up and down inside an elevator shaft. To find the tension force, you use the formula F=mg, where m is the mass and g is the gravity constant of 9.8 m/s². 
4. As the students plot points in the worksheet, ask them to identify the x-axis and the y-axis. After the students plot the points on the two graphs, ask the students what the lines represent after connecting the ordered pairs. 
5. Ask the students to draw each polygon next to its name on the worksheet. What characteristics make the polygons different? Have the students create a repeating pattern of the shapes, like in the Forces, Scatterplot, and Polygons Worksheet Answer Key. How can a repeating pattern of shapes help determine the weight it can hold?
3. In their groups, the students should research more about their project and record their research in the “Day 2” section of the Student Log Book. Have students consider the following questions: What does a materials engineer do? Can you find any examples of specific jobs that this type of engineer might do? What kind of materials do manufacturers use for a sled hockey? What kind of testing do engineers use when designing hockey sticks? Are there any factors you may need to remember when designing your stick? In regard to structures, are there any advantages or disadvantages of some polygons used? Distribute a copy of the Engineering Design Process Rubric to each student group. Have students perform self-assessment throughout the project using this rubric. 
4. Instruct students to complete “Day 2” questions in the Student Log Book. 

Day 3

1. Review the engineering design process, particularly steps 1 through 3. Pass out copies of the Engineering Design Process Handout. 
2. In their groups, students will begin using their research and materials to begin designing their sled hockey stick. 
3. After they have brainstormed, instruct the students to choose the best solution. 
1. Remind them they are on step 4 of the engineering design process: selecting the best possible solution.
4. The students will begin construction of their hockey stick. During this time, encourage the students to experiment with all of the available materials. Remind them that dimensions (or constraints) are an important part of designing the stick.
5. Before asking the students to complete log book questions, read the Testing Procedures Sheet so that they have a sense of what the testing procedure is. 
6. Instruct students to complete “Day 3” questions in the Student Log Book. Ask the students to discuss the questions as a group and then prepare to share their answers with the class. 

Day 4

1. Instruct the students to continue to work on their sled hockey stick design. As the students work, circulate the room to check on their progress. Ensure that students are using their design and materials to create their hockey stick. Probing questions for each group may include:
1. Why did you choose this material over another material? 
2. Did you include a polygon inside the stick? Why or why not? 
3. Is the brainstorming part of the design process helpful? What if you didn’t discuss possible solutions with your group?
2. Once students complete their designs, instruct them to being testing. Provide each group with copies of the Testing Procedures Sheet. 
1. Create a chart in the lab book following the example on the Testing Procedures Sheet. 
2. Wrap one pipe cleaner around the stick, 4 cm (1.5 in) from the end. 
3. Place the stick on a table and tape about 10 cm (4 in) of the stick’s length down with duct tape.
4. Have one student from the group hold a meter stick from the ground to the end of the stick, near the pipe cleaner. Note the centimeter mark at the bottom of the stick. 
5. Direct the students to add one weight to the stick using the pipe cleaner. Did the stick’s height (according to the meter stick) change in any way? Have students document the weight and the change in flexure. If there is no change, put 0 in the right column. 
6. Continue to add weight and document changes until the stick breaks.  
7. Students should take pictures to document and validate progress during testing.
8. Once the students begin testing, remind them that they are on step 6 of the engineering design process.
3. Students should complete “Day 4” questions in the Student Log Book.
4. Discuss with the students where the normal and tension forces occur during testing.
1. Normal force occurs on the end of the stick that is taped to the table.
2. Tension force occurs on the end of the stick holding the weights. 

Day 5

1. If there are groups that still need to test, instruct them to finish testing and collecting data.
2. Explain to the students that they are still working on step 6 of the engineering design process. Ask the students what they think about the importance of this step. (Possible answers include: organizing ideas and results so they can be easily evaluated; sharing results to get feedback from others, etc.)
3. Instruct the students to plot their data on a piece of graph paper. 
1. Remind the students to label the axes: x-axis is weight and y-axis is deformation. 
4. Direct the groups to discuss what this data may represent. 
1. Where did your stick break?
2. Did it withstand a lot of weight? Why or why not?
3. What would make their design better?
5. Ask groups to present their graphs. They should share what they think went well for them and what they should change during the step of redesign. 
6. Students should complete “Day 5” questions in the Student Log Book. 

Day 6

1. With their collection of data as well as ideas from other groups, the students will redesign their sticks. 
1. Have the students brainstorm ideas before using the materials. 
2. What is your approach for this redesign in the 7th step of the engineering design process?
3. Are there materials or ideas you will keep for your second design? Which materials will you get rid of? 

Day 7

1. Instruct students to complete their redesign. 
2.  Have the groups present on their iterations. 
1. What materials were different? 
2. What polygon structure did you choose? Is it different than your initial design? Why or why not? 
3. Pass out the Pre/Post-Quiz and have students complete it. 
4. When done with the test, direct students to complete the “Final Day” questions in the Student Log Book.

Vocabulary/Definitions

flexure test: A way to examine the behavior of a slender structure that is subjected to an external load; also known in engineering as bending of a particular object.

force: In physics, any interaction that, when unopposed, will change the motion of an object.

materials engineering: The design and discovery of new materials that emphasizes how processing influences an object’s structure as well as its properties and performance.

normal force: In mechanics, a component of a force that is perpendicular to the surface that an object contacts; for example, the surface of a table that prevents an object lay on top of it from falling.

sled hockey: Hockey game adapted for those with physical disabilities; participants use an ice sled and two sled hockey sticks to maneuver around the rink.

tension force: In physics, the act of pulling by means of a string, cable, or chain and the force exerted on such an object as it is being pulled.

Assessment

Pre-Activity Assessment

Pre-Quiz: In advance of starting this activity, have students complete the Pre/Post-Quiz. Review their answers to gauge their mastery of the pre-requisite concepts.

Activity Embedded Assessment

Log Book: Students should complete the Student Log Book. The log book questions will be a way for the students to reflect on what they did that day for the activity and how it will help them in the process. Have students perform self-assessment using the Engineering Design Process Rubric.

Post-Activity Assessment

Post-Quiz: At activity end, re-administer the Pre/Post-Quiz. Compare students’ pre and post scores to determine their knowledge gains from conducting the activity.

Troubleshooting Tips

• If weights are not readily available for this activity, create your own with any half-kilogram amount of material (such as sand) and fill a Ziploc bag. Make sure to label the weight of each bag.  
• If the weight set you are using does not increase by half-kilogram (or even kilogram) increments, have the students keep the weight column of their table blank until they test. As the put on the weights, fill in the rows according to the amount of weight added to the stick test.

Activity Scaling

• For lower grades, remove the polygon structure aspect from the activity. Simplify testing by placing the stick on a desk and stacking textbooks on the stick, one at a time, to observe the strength of the materials.  
• For higher grades, the students could use the force formula to find how much force the stick can withstand. Students could also create a stick that has the paddle at the end, like an actual sled hockey stick.

Additional Multimedia Support

Gatorade – Sledge Hockey: https://www.youtube.com/watch?v=9gsy9Som_xs

Hockey Stick Flex and Breaking Point Test: https://www.youtube.com/watch?v=J57TP5TrNwg

Copyright

Contributors

Supporting Program

Acknowledgements

This material is based upon work supported by the National Science Foundation under grant no. EEC 1405869—a collaborative Research Experience for Teachers Program titled, “Inspiring Next Generation High-Skilled Workforce in Advanced Manufacturing and Materials,” at the University of Dayton, Central State University, and Wright State University in Ohio. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.