Student Exploration: Crumple Zones
Vocabulary: acceleration, airbag, collision avoidance system, crash test dummy,
crumple zone, force, kinetic energy, Newton’s laws of motion, 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 concrete wall.
1. Who do you think will be hurt more in the collision, and
why?
Jack who is carrying a metal safe would be more hurt
because the impact of the safe against the concrete wall is
more than an armful of quilts
2. During a car crash, what features of the car might act like either Jack’s safe or Jill’s
quilts?
During a car crash, the impact of the metal cage and steering wheel acts like Jack
carrying a safe and Jill’s quilts act like the airbags of the car as they relieve the
impact.
Gizmo Warm-up
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?
2019
, The airbag and seat belt are missing. Due to this, the crash dummy goes forward
hitting it’s neck on the wheel and the front of the car gets totaled.
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. No because the impact of
the car against the wall would lead to trauma/injuries the in head and torso.
Get the Gizmo ready:
Activity A:
• Click Reset ( ).
Surviving a
• On the DESIGN tab, check that Sedan is
crash
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: 120 cm Crumple zone rigidity: 200 kN
Safety cell rigidity: 2000 kN
Seat belt present? Yes If present, seat belt stiffness: 50 kN/m
Air bag present? Yes If present, air bag rigidity: 0 kN
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? 77% Safety cell? 5%
B. Did the dummy hit the steering wheel? No
C. What was the maximum force on the dummy? 14.25 kN
2019