Warning: Undefined array key "file" in /www/knowledgecenterh_807/public/wp-includes/media.php on line 1768
Deprecated: preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in /www/knowledgecenterh_807/public/wp-includes/media.php on line 1768
Minimizing Forces During a Collision
A Carolina EssentialsTM Activity
Total Time: 45-60 mins
Prep: 20-30 mins | Activity: 45-60 mins
Physical Science, Physics
9-12
High School
- Total Time: 45-60 minutes [ Prep: 20-30 mins | Activity: 45-60 mins ]
- Subject: Physical Science, Physics
- Grade: High School
Overview
Many students have had the opportunity to participate in an egg drop activity in which they design a container to protect an egg dropped from a designated height. In this activity, students design a car “bumper” to absorb the force of a pendulum colliding with a frictionless cart. Students utilize and apply concepts including force, energy transformation, conservation of energy, momentum, conservation of momentum, and Newton’s laws of motion. A well-designed bumper should absorb the force of the pendulum striking it, resulting in minimum displacement of the car. This activity can also be used as a design challenge after students research automotive safety design and technologies like air bags, crumple zones, and seat belts.
Phenomenon
Look at the photograph of this front-end wreck carefully. What would you ask the automotive engineer about the design and construction of this car?
Essential Question
What general characteristics must be engineered to minimize the force on an object during a collision?
Activity Objectives
- Generate and evaluate evidence describing the magnitude of force when a collision occurs.
- Design, test, and refine a modification for the Hall’s car to minimize the force on the car during a collision.
Next Generation Science Standards* (NGSS)
PE HS-PS2-3. Apply scientific and engineering ideas to design, evaluate, and refine a device that minimizes the force on a macroscopic object during a collision.
SCIENCE & ENGINEERING PRACTICES
Constructing Explanations and Designing Solutions
- Apply scientific ideas to solve a design problem, taking into account possible unanticipated effects.
DISCIPLINARY CORE IDEA
PS2.A: Forces and Motion
- If a system interacts with objects outside itself, the total momentum of the system can change; however, any such change is balanced by changes in the momentum of the objects outside the system.
ETS1.C: Optimizing the Design Solution
- Criteria may need to be broken down into simpler ones that can be approached systematically, and decisions about the priority of certain criteria over others (tradeoffs) may be needed.
CROSSCUTTING CONCEPTS
Cause and Effect
- Systems can be designed to cause a desired effect.
Materials
- 1 Support stand with ring/ group
- 1 Hall’s Car-Frictionless cart/ group
- 1- 2-hole stopper size 8, 9, or 10/ group
- 60 cm of String/ group
- Metric ruler
- Duct tape to affix the bumper to the Hall’s cart
- Rubber bands to affix the bumper to the Hall’s cart
- Bumper materials (examples include: balloons, cotton balls, packing peanuts, water, paper, facial tissue, other items students request, and snack size resealable bags for housing bumper materials)
Safety Procedures and Precautions
Students should wear safety glasses and avoid unintended contact with the swinging stopper.
Teacher Preparation and Disposal
To save set-up time, prepare materials for each table. You may construct the pendulum before the activity then store a permanent class set.
SCIENCE & ENGINEERING PRACTICES
A. Pendulum Construction
- Place the support stand ring about 8-10 inches from the top of the support stand rod and tighten securely.
- Thread the string through the smaller end of one hole of the stopper and then back up through the second hole and tie the string securely.
- Tie the stopper pendulum to the ring so the stopper will contact the Hall’s car on the flat, narrow side of the car, (back side).
- Place the set-up on the floor so there is room for the car to travel.
B. Initial State Testing
- Place the back end of the car directly next to the base of the ring stand so the stopper will collide with the back side of the car.
- Keeping the string taut, raise the stopper pendulum until the string is parallel with the floor. Measure the distance from the floor to the stopper in centimeters.
- Release the stopper so it hits the car.
- Measure the distance the car travels from the base of the pendulum in centimeters.
- Repeat the procedure for a total of five trials.
Design a Bumper
- Using the materials available, design, test, and refine a force absorbing bumper for the Hall’s car.
- Test your design and refinements at least five times.
- Take a picture or sketch your final design.
TEACHER PREPARATION AND TIPS
- You may wish to tie the stoppers yourself to save some time. The size of stopper can vary between groups but needs to remain the same within a group.
- Check groups to ensure the stopper is colliding with the back of the car.
- Make sure there is adequate floor space for the cars to travel unimpeded.
- Allow students to try materials before deciding on a design to test.
- Pictures can be inserted into the activity write-up.
Data and Observations
Design Evaluation Data
Analysis & Discussion
Use the engineering design cycle as a framework, your data, and physics concepts to make a written recommendation for directions to reduce force on the Hall’s cart during a collision.
Student answers will vary but must include all tasks within the design cycle and the evidence to support their revisions.
Use what you have learned through the engineering process as evidence to explain why the car in the phenomenon picture has a crumpled front end but an in-tact driver’s compartment.
Student answers will vary but must include evidence generated during the engineering process applied to the picture of the wrecked car.
SHOP THE KIT
SAFETY REQUIREMENTS
- Safety Goggles Required
REFERENCE KIT
HELPFUL LINKS
- Infographic - The Engineering Design Cycle and NGSS Dimension 1: Engineering Practices
- Carolina Engineering & Design Process Worksheet
- Engineering & Design Vocabulary
- STEM Activities for Interdisciplinary Teams
- Carolina STEM Challenge® 2.0
- Carolina STEM Challenge®: Egg Drop Kit: Product Feature Video
VIEW MORE ESSENTIALS
*Next Generation Science Standards® is a registered trademark of Achieve. Neither Achieve nor the lead states and partners that developed the Next Generation Science Standards were involved in the production of, and do not endorse, these products.
RELATED RESOURCES
