deformed guard rail

Students will learn about the construction of road barriers and how they protect drivers.

In this lesson, students will construct an egg catcher that will catch an egg from the greatest possible height without cracking or breaking the egg. The egg catcher will function as a barrier, similar to guard rails along a highway, which will cushion an egg’s drop. This lab allows students to use problem solving to create a design that will increase contact time of the egg and barrier to minimize the force upon the egg.

Learning outcomes

Students will:

  • Design an egg catcher that functions as a barrier that will protect an egg from injury
  • Test the efficacy of the egg catcher
  • Evaluate the success of their design and the designs of other groups
  • Gain experience and comfort in public speaking

Teacher planning

Time required

two class periods

Materials needed

Each group will need:

  • aluminum pie tin
  • 3 meters string
  • paper clasp
  • 2 rubber bands
  • nail
  • 6-inch × 6-inch piece of felt
  • 30 centimeters of tape
  • scissors
  • one of the following:
    • Ziploc bag of cotton balls
    • 4-inch × 4-inch square of bubble wrap
    • Ziploc bag of packing popcorn

Student handouts

Group five expert interview: Barrier design
Document by the author
Open as PDF (18 KB, 3 pages; also available as Microsoft Word document)
Lab: Egg drop to test barrier design
Document by the author
Open as PDF (15 KB, 2 pages; also available as Microsoft Word document)
Quiz: Barrier design
Document by the author
Open as PDF (11 KB, 1 page; also available as Microsoft Word document)

Activities

Day one

  1. Group Five will present the Barrier Design expert interview.
  2. Inform students that they will be designing an egg catcher that will function as a barrier, much like the guard rails along a highway. They should incorporate the information they learned from the expert interview in their designs.
  3. Explain to students the guidelines for their egg catcher designs.
    • Only the materials provided may be used in constructing the device.
    • They can use scissors.
    • The catcher must be free-standing. It may not be attached to the floor or ceiling in any way.
  4. Before students begin their designs, explain how the egg catchers will be tested. Each team is responsible for aiming and dropping the egg onto their device. They may use any of the materials provided to help aim drop. All teams will drop their eggs from the same heights at approximately the same time. The drops will be from heights of 40 cm, 60 cm, 80 cm, 1 m, 1.5 m, 2 m, 2.5 m, 3 m, and 4 m. There will be about one minute between each drop. Students are allowed to repair their devices if needed but no extra supplies will be provided.
  5. Distribute the lab sheets to students.
  6. Before using any of the materials, have students brainstorm design ideas.
  7. Students work in their groups for the rest of the class period designing and constructing their egg catchers. Remind them to list the materials they use on their lab sheets.

Day two

  1. Tell students that today they will be testing the egg catcher barrier designs. Remind students of the guidelines for testing:
    • Each team is responsible for aiming and dropping the egg onto their device.
    • All teams will drop their eggs from the same heights at approximately the same time. The drops will be from heights of 40 cm, 60 cm, 80 cm, 1 m, 1.5 m, 2 m, 2.5 m, 3 m, and 4 m. Each team will drop the egg from each height until the egg breaks or cracks. Once the egg breaks or cracks, that team is disqualified from further competition.
    • There will be one minute between each drop. Groups are allowed to repair their device if needed but no extra supplies will be provided.
    • When your team receives an egg, check it over carefully for any cracks.
    • There will not be practice drops.
  2. Have groups test the eggs according to the guidelines. Make sure you circulate and monitor student testing.
  3. After testing the eggs, students should independently complete the questions on their lab sheets.
  4. During the last five to ten minutes of class have students complete the short quiz.

Assessment

Check student answers on the lab sheet for completeness and understanding.

Students will also take a short quiz comprised of the following questions. Check their answers for understanding of barrier design concepts.

  1. If you could make two changes to the materials list for this lab what would it be and how would it change your barrier design?
  2. If you were a driver on a North Carolina interstate, what barrier designs would most effectively reduce injuries from accidents? This answer may include drawings with your explanation.

  • North Carolina Essential Standards
    • Science (2010)
      • Grade 7

        • 7.P.1 Understand motion, the effects of forces on motion and the graphical representations of motion. 7.P.1.1 Explain how the motion of an object can be described by its position, direction of motion, and speed with respect to some other object. 7.P.1.2 Explain...
      • Physical Science

        • PSc.1.2 Understand the relationship between forces and motion. PSc.1.2.1 Explain how gravitational force affects the weight of an object and the velocity of an object in freefall. PSc.1.2.2 Classify frictional forces into one of four types: static, sliding,...

North Carolina curriculum alignment

Science (2005)

Grade 8

  • Goal 1: The learner will design and conduct investigations to demonstrate an understanding of scientific inquiry.
    • Objective 1.01: Identify and create questions and hypotheses that can be answered through scientific investigations.
    • Objective 1.05: Analyze evidence to:
      • explain observations.
      • make inferences and predictions.
      • develop the relationship between evidence and explanation.
    • Objective 1.06: Use mathematics to gather, organize, and present quantitative data resulting from scientific investigations:
      • Measurement.
      • Analysis of data.
      • Graphing.
      • Prediction models.
  • Goal 2: The learner will demonstrate an understanding of technological design.
    • Objective 2.02: Use information systems to:
      • Identify scientific needs, human needs, or problems that are subject to technological solution.
      • Locate resources to obtain and test ideas.
    • Objective 2.03: Evaluate technological designs for:
      • Application of scientific principles.
      • Risks and benefits.
      • Constraints of design.
      • Consistent testing protocols.