(Lesson courtesy of Lessonopoly and NBCLearn) Level: Grades 6-8. Time Required:  Two 50 minute periods.

Students will learn the basic engineering issues related to helmet design, specifically, they will learn about the physics of collisions and the biomechanical considerations of design. After learning about the basic principles, students will identify and solve a design challenges, create a poster representation of their solutions, and present them their peers. Finally, students will learn about the dangers of not wearing a helmet in certain sports, and explore the reasons that people do not wear helmets.

CALIFORNIA STATE STANDARDS

Science/8/Focus on Physical Science
1.0 The velocity of an object is the rate of change of its position. As a basis for understanding this concept: a. Students know position is defined in relation to some choice of a standard reference point and a set of reference directions. b. Students know that average speed is the total distance traveled divided by the total time elapsed and that the speed of an object along the path traveled can vary. c. Students know how to solve problems involving distance, time, and average speed. d. Students know the velocity of an object must be described by specifying both the direction and the speed of the object. e. Students know changes in velocity may be due to changes in speed, direction, or both. f. Students know how to interpret graphs of position versus time and graphs of speed versus time for motion in a single direction.

2.0 Unbalanced forces cause changes in velocity. As a basis for understanding this concept: a. Students know a force has both direction and magnitude. b. Students know when an object is subject to two or more forces at once, the result is the cumulative effect of all the forces. c. Students know when the forces on an object are balanced, the motion of the object does not change. d. Students know how to identify separately the two or more forces that are acting on a single static object, including gravity, elastic forces due to tension or compression in matter, and friction. e. Students know that when the forces on an object are unbalanced, the object will change its velocity (that is, it will speed up, slow down, or change direction). f. Students know the greater the mass of an object, the more force is needed to achieve the same rate of change in motion. g. Students know the role of gravity in forming and maintaining the shapes of planets, stars, and the solar system.

PROCEDURES

Goal(s):

Students will learn about basic physics and biomechanical aspects of helmet design. As a class, the design parameters will be created and students will make a two-dimensional sketch of their design idea and a written description. Students will learn about the risks of not wearing helmets and create ways to encourage others to wear helmets.

Objectives:

Students will be able to:

1. Identify that the helmet is the most important piece of safety equipment in the winter Olympics and many other sports.
2. Describe how the helmet absorbs and dissipates energy in a collision.
3. List at least 3 functional performance parameters for a helmet.
4. Create a solution strategy for a helmet design challenge.
5. Present and explain their design solutions to the class.
6. List at least 2 common reasons why people do not wear bicycle helmets.

Required Materials:

At least few example safety helmets (baseball, football, hockey, bicycle, motorcycle, ski, etc.), styrofoam block, 5 pound weight, poster board or large paper (11 x 17 or larger), pencils, erasers, and markers or colored pencils.

Anticipatory Set (Lead-in):

Raise your hand if you have ever played hockey, been on a motorcycle, skied, skateboarded, been snowboarding, etc.?

Raise your hand if you have ever been injured doing any of these activities?

Today’s lesson will cover some of the basics of safety equipment in winter Olympic sports and particularly focus on the most important piece of equipment. Pair-Share with your neighbor to see if you can agree as to what is the most important piece of safety gear.

At this point, bring the conversation to bicycling and ask students for a show of hands of everyone who either rides a bicycle or plans to at some point in their life. Now ask them the following questions and discuss the answers:

Does anyone know how many people might die in a year due to bicycle accidents?
• Most years close to 1000 bicyclists die on U.S. roads.

Do bicycle helmets actually help prevent fatalities?
• Non-helmeted riders are 14 times more likely to be involved in a fatal crash than helmeted riders.
• Head injuries account for more than 60 percent of bicycle-related deaths.
• A very high percentage of cyclists’ brain injuries can be prevented by a helmet, estimated by different studies at anywhere from 45 to 88 per cent
(Source: http://www.bhsi.org)

Lesson Plan Procedure:

Note: This lesson assumes some familiarity with energy concepts such as kinetic energy and dissipated energy. If students are not familiar with these terms then they should be clarified before watching the video.

Day 1 Part I: The Physics and Engineering Performance Parameters of Helmets (30 Minutes)

1. Orally go over the questions on the worksheet “Video Questions: Safety Gear”. Don’t answer the questions, just read them, and tell the students that they will be answering them after the video.
2. Show the NBC Learn Video: Safety Gear, then hand out and go over the worksheet answers as a class.
3. *Optional Step (Use caution when dropping the weight in this optional step.) When discussing the absorption of energy during a collision, you can do a demonstration by dropping a 5 lb weight on a piece of Styrofoam, observing the deformation, passing around the sample around, and discussing the energy dynamics (gravitational potential energy to kinetic energy which is then absorbed by the foam and dissipated, creating thermal energy).
4. Pass around various types of sample helmets and discuss similarities and differences. (When discussing similarities you should make sure they recognize the outer shell and inner foam.)
5. Hand out the activity worksheet. And begin by defining the term, performance parameters. (“A set of qualities which characterize particular aspects, capabilities, functions, or attributes of a project.”).
6. Through small group discussions (with whiteboards if you have them) or as a whole-class discussion, create a list of performance parameters for a bicycle helmet. The list should include functions like those listed in the video: force distribution, energy absorption, and puncture resistance. It may also include performance parameters that may arise through discussion: ventilation, aerodynamics, mechanism to secure to head, light weight, aesthetics, and high visibility both day and night.

Day 1 Part II Design and Marketing Challenge (20 Minutes)

1. Having discussed performance parameter of helmets, now ask your students to brainstorm problems or challenges associated with helmets in general (not just bicycling helmets).
2. Create a class list which can be supplemented with the attached list “List of Possible Design Challenges.” Assign each group one design challenge.
3. Provide time for groups to brainstorm and list as many creative solution ideas as possible, both design modifications and marketing, (encourage them to think outside-the-box, perhaps even discuss why, and to consider current technologies and perhaps even a few on the horizon.)
4. After creating a list of ideas, students need to identify (circle or rewrite) the best solution strategies.
5. Explain the attached grading rubric, and the general expectations for the presentations.
6. Creating the posters and presentations can either be assigned as homework or completed the following day.

Day 2 Creating Poster and Presenting Solution Ideas.

1. Provide class time, if needed, to make posters and prepare presentations.
2. The attached presentation grading rubric can be filled out by the teacher or by selected judges.
3. Give Quiz: Olympic Safety Gear and Helmets

Closure (Reflect Anticipatory Set):

Ask students whether or not they feel differently about helmets after this lesson. Ask them what they can personally do to better insure that people they care about do not suffer from head injuries.

Assessments & notes

Assessment Based on Objectives:

Attached Grading Rubric
Quiz: Olympic Safety Gear and Helmets

Possible Connections to Other Subjects:

Language Arts: Write a paper on helmet issues based on general research on safety issues and statistics (http://www.bhsi.org).

Adaptations & Extensions:

Physics extensions could involve doing laboratory investigations on the conservation of energy, collisions, momentum, and the extension of the time variable in the impulse equation Impulse=Force x Time.

Additional Notes:

This lesson assumes some familiarity with energy concepts such as kinetic energy and dissipated energy. If students are not familiar with these terms then they should be clarified before watching the video.

Filed under: Grades 6-8, Lesson Plans

Tags: Engineering Design, Safety engineering, Sports, Sports Engineering