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University of Nebraska–Lincoln

Transportation Systems Engineering

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Lesson Overview
Lesson Title:
Car Crash Barriers

Dr. Wally Mason (Primary)

Brief Description:
Students will use inquiry to build a barrier out of given supplies that will lessen the force of a concrete block on a friction car.

Topics Introduced:
Newton's Laws

Transportation, Distribution, and Logistics Curriculum Framework Components Addressed:
Health, Safety and Environmental Management
Suggested Grade Levels:
7th Grade
8th Grade

Standards Taught:
8.2.1 Science 2003

Lesson Information
Learning Expectations:

1. Students should be able to visualize the force exerted on an an automobile to during a collision
2. They should visualize how a barrier can decrease deceleration and in turn decrease force exerted on a car
3. Students will be able to examine how extra mass affect the force exerted on a car during an accident.

Plan Of Action:

1. I will instruct via powerpoint or other technological tools on Newton's three laws and how they apply to the forces exerted during car accidents.
2. Students will take their knowledge of Newton's second law and begin the building of a barrier that will increase the deceleration involved in a car accident.
3. Students will test the force exerted on a crashing car using a calibrated force system involving small rulers and clay. They will perform three to five trials with equal mass and average the values to get a normative crash force.
4. Students will then build a barrier out of supplies and when barrier is finished they will again run three to five trials with equal mass to get a crash barrier force value. This value in theory should be less.
5. There will multiple crash car stations each car will be laden with its own unique mass so that students can see how increased or decreased mass affects force. The car itself will have the same mass
6. There will then be a short conclusion section that will need to be filled out by students after the data collection.

Data Set Used:

students will measure force in mm of displacement of a ruler during a collision with a barrier and without a barrier

students will measure mass in g using an electronic scale

students will use data table to average force values

Materials Needed:

each group will need

1. one friction car
2. large washers for mass
3. sturdy clay, about a half a cup or one stick
4. 10 straws
5. 1 meter of masking tape
6. 10 cotton balls
7. 10 Popsicle sticks
8. 10 x 10 cm square of aluminum foil
9. At least a 30 cm ramp
10. concrete block
11. 3-4 cm ruler with mm visible
12. electronic balance
13. one half popsicle stick

Preparation Period:

This lesson will last at most two 52 minute periods, I will intro Newton's Laws, model how to find the displacement of the ruler and document that in the data table, and I will hand out supplies for barrier. My preparation involves getting the cars and clay and supplies separated into the appropriate amount of groups. Student preparation involves listening to intro.

Implementation Period:

Two 52 minute periods

Science, Math, Engineering and / or Technology Implications:

Students will use all of Newton's laws and they will see how the mathematics of the second law applies to force exerted on an automobile during a crash. They will use calibrated force measurements and inquiry to determine if a barrier that they built can decrease the force exerted by concrete wall on a colliding car.

Unexpected Results:

we'll see, updated later

Considerations for Diversity in Education:


Lesson Files
Homemade Crash Barrier Experiment
INCLUDES: title, Question, hypothesis, materials, method, data, interpretation, conclusion questions
[size: 42496] [date uploaded: Jul 14, 2009, 3:55 pm ]

smart car crash
smart car crash
[size: 3503010] [date uploaded: Jul 14, 2009, 9:40 pm ]

sliding cars
sliding cars
[size: 3315310] [date uploaded: Jul 14, 2009, 9:49 pm ]

air bag test video
air bag test video
[size: 304055] [date uploaded: Jul 14, 2009, 9:50 pm ]

Homemade Crash Barrier Experiment powerpoint
[size: 428544] [date uploaded: Jul 14, 2009, 9:52 pm ]

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