5. What Is Crumple Zone?
Crumple zones are a design feature of an
automobile. They have the primary function
of absorbing the energy from a collision. They
are part of the body of a car and are designed
to ‘crumple’ under impact, rather than retain
their structural integrity and therefore resist
the force being applied to them. This means
that only this smaller area crumples, keeping
the passenger area intact.
6. ENGAGE
• How do the crumple zones work?
• What is involves in the crumple zones activity
and what is the relationship between them?
• What types of material is used to make the
most effective crumple zones?
7. EMPOWER Data
Logger
Planning and Doing Experiment
Interface
Momentum Sensor
Trolley
Computer
track
Figure 1- Pasco attached to cart on a track
8. EMPOWER
Planning and Doing Experiment
monitor Power supply
Pasco SENSOR
trolley
track
Figure 1- Pasco attached to cart on a track
9. RESULTS
Maximum Stopping Acceleration Time to stop
(m/s ) (s)
Without Crumple Zones >60 0.005
With Crumple Zones Heavy- Duty Aluminium Foil Standard Aluminium Foil
Maximum Stopping Time to stop Maximum Stopping Time to stop
Acceleration (s) Acceleration (s)
(m/s ) (m/s )
1 Foil Cylinder 9.40 0.113 >60 0.728
2 Foil Cylinder 9.47 0.064 6.28 0.120
3 Foil Cylinder 14.44 0.050 7.25 0.092
4 Foil Cylinder 15.26 0.047 7.80 0.070
12. QUESTIONS
1. What is the relationship between the maximum stopping
acceleration and the maximum stopping. Force experienced by the
cart? What physics principle is the relationship based on?
2. What is the relationship between the maximum stopping
acceleration and the time it takes the cart to stop? What physics
principle is the relationship based on?
3. What is the relationship between the number of cylinders and the
maximum stopping acceleration for the heavy-duty foil? Does this
same relationship hold for the standard foil? Explain.
4. Based on your data, which crumple zone was the most effective?
Which was the least effective? Explain your reasoning.
13. ANSWERS TO QUESTIONS
1. The maximum acceleration and force are directly related. As one goes up so does the
other. This is Newton’s 2nd Law.
2. The maximum acceleration and time to stop the cart are inversely related. As the
maximum acceleration increases, the time to stop the cart decreases. This is based on
the impulse-momentum theorem. Given the carts all have the same change in
momentum, they all require the same impulse to stop the cart. The cart with the
largest average acceleration will stop in the shortest amount of time.
3. Answers will vary. For our data, as the number of cylinders increased, the maximum
acceleration increased. This is a result of the increased “stiffness” of the crumple
zones. This was not the case for the standard foil where a single cylinder was not able
to significantly slow the cart before it impacted the end stop. For two or more
cylinders, the results were similar to the heavy-duty foil.
4. Answers will vary. From our data, the best crumple zone was the two cylinder,
standard foil crumple zone. This had the smallest maximum stopping acceleration
and the longest stopping time. The worse crumple zone was the single cylinder
standard foil. The cylinder was completely flattened, allowing the cart to impact the
end stop with a force comparable to the collision without a crumple zone.
14. ENHANCE
PHASE
WHAT IS CRUMPLE ZONE??
Crumple zone is designed so that the structure of the car
will give way during collision.
15. How crumple zone work??
• The metal of the car will dent, bend and fold
during collision
• They help reduce injuries by changing shape
and absorbing energy through progressive
• It controlled and reduced acceleration of the
vehicle. A good crumple zone will mean that a
car stops in a longer time and longer distance
16. what is involves in the crumple zone
activity ??
Crumples zones involve concept of conservation of
momentum and conservation of energy.
The momentum change of the vehicle for a given
speed is the same as the change in kinetic energy.
By increasing the time of the collision and the
distance which collision occurs, it can reduce the
amount of force needed to stop the vehicle.
This also reduce the amount of force that acts on
the passengers
17. What the material that used in
crumple zone??
Firstly, crumple zone have high
Secondly, reinforced fibres and
density polymeric foam which
spaced between the high
contains more tightly formed
density polymeric foam and
molecules to make the foam
the low density foam
strong, this is places in front
of the cabin
Thirdly, the foam is caged in Lastly, the front end of the car
mechanical ribs made from is built with steel or titanium.
either steel or titanium and These metal piece are
have been specifically reinforced with notched metal
designed to crush inserts which will cause the
downwards under the car metal to either crush
