Student Exploration: Crumple Zones
Vocabulary: acceleration, airbag, collision avoidance system, crash test dummy, crumple zone,
force, kinetic energy, N... [Show More] eZWon¶s laZs of moWion, safety cell, seat belt, work, work-energy theorem
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
Two burglars run down an alley at night, trying to escape the cops.
Jack is carrying a rigid metal safe. Jill is carrying an armful of
antique quilts. In the pitch dark, they both collide headlong into a
1. Who do you think will be hurt more in the collision, and why?
2. During a car crash, what features of the car might act like either Jack¶s safe or Jill¶s qXilWs?
When cars were first invented, the safety of passengers was
not a great concern. As vehicles grew larger and faster,
accidents became more deadly. Safety features went from
being a rare luxury to a legal requirement. In the Crumple
Zones Gizmo, you will design cars that will help a crash test
dummy survive a collision.
1. To begin, do not make any changes to the DESIGN tab of the Gizmo. Select the CRASH
TEST tab, and click Play ( ). After the crash, click Slo-mo replay. What happens?
2. Select the RESULTS tab to read about the results of the crash. Do you think a passenger
would have survived this car crash? Explain.
Jackwill behurt morebecause therigidsafewill hit himwinthesame force thatithits the
wall but Jill hasquilts tocushion theimpact
Duringacar crashmerigidframe will act likeJack'sasewhiletheairbags will actlikeJill'squiltrelieving pressureandimpact
Thecar crashesinto a concretewall and pieces ofglassflyoff the windshield
A passengerwouldn't be able
to survive this crash because of trauma to theheadandtorso
This study source was downloaded by 100000826192319 from CourseHero.com on 09-13-2021 05:13:47 GMT -05:00
This study resource was
shared via CourseHero.com2019
Surviving a crash
Get the Gizmo ready:
x Click Reset ( ).
x On the DESIGN tab, check that Sedan is selected.
Introduction: Modern vehicles contain features designed to keep passengers safe in a crash.
The crumple zone in the front of the car slows the car gradually and increases stopping time.
The safety cell is a rigid cage that prevents passengers from being crushed. Inside, seat belts
and airbags prevent the driver from hitting the windshield, steering wheel, or dashboard.
Question: How does a crumple zone help protect a passenger?
1. Make a hypothesis: On the DESIGN tab, look at the parameters you can control. What
settings do you think will make the safest car? Set up the Gizmo, and then fill in below.
Crumple zone length: Crumple zone rigidity: Safety cell rigidity:
Seat belt present? If present, seat belt stiffness:
Air bag present? If present, air bag rigidity:
2. Test: On the CRASH TEST tab, check that the Car 1 speed is 16 m/s, or about 35 miles per
hour (mph). Click Play. After the crash, select the RESULTS tab.
A. By what percentage did the crumple zone deform? Safety cell?
B. Did the dummy hit the steering wheel?
C. What was the maximum force on the dummy?
D. How likely was the dummy to survive?
In this simulation, forces are measured in kilonewtons (kN). One kilonewton is equal to 1000
newtons, or the force of a 225-pound (102 kg) person standing on your chest. While many
factors affect survival, only the maximum force and safety cell collapse are considered here.
3. Experiment: On the DESIGN tab, set the Crumple zone length to 100 cm and the Safety
cell rigidity to 2000 kN. Set the Seat belt stiffness to 50 kN/m and turn off the Airbag. For
each Crumple zone rigidity setting, run a 16 m/s crash test and enter the results below. [Show Less]