Collision Engineering

Collision Engineering

Middle School

​

Learning Objectives

• Define key terms including kinetic energy, impulse, and concussion.

• Explain how safety features protect passengers by managing forces over time.

• Apply Newton's Third Law to design solutions for collisions.

• Define criteria and constraints for an engineering design problem.

• Explain the importance of iterative testing and data analysis in optimizing safety features.

Key Vocabulary

​

Kinetic Energy

Kinetic energy is the energy an object possesses because of its motion.

​

Impulse

Impulse is a force that is applied over a period of time to cause a change in motion.

​

Crumple Zone

A crumple zone is a part of a car designed to crush and absorb impact energy during a collision.

​

Newton's Third Law

Newton's Third Law states that for every action, there is an equal and opposite reaction.

​

Concussion

A concussion is a type of brain injury that occurs from a sudden impact to the head.

​

Criteria

Criteria are the specific standards or requirements used to evaluate the success or failure of a design.

Key Vocabulary

​

Constraints

These are limitations placed upon a design, which can include factors like project cost or available materials.

​

Iterative Testing

This is the process of repeating tests over and over to refine and improve a design.

​

System Model

This is a representation of a complex system and all of its individual parts and functions.

The Physics of a Collision

• More speed and mass mean more energy and damage.

• A car hits a wall, and the wall pushes back with equal force.

• This interaction of forces causes damage to the vehicle.

Multiple Choice

When a car collides with a wall, how does the force the wall exerts on the car compare to the force the car exerts on the wall?

• The forces are equal and opposite

• The wall exerts more force than the car

• The car exerts more force than the wall

• The wall does not exert any force

Multiple Choice

What is the primary reason that damage occurs to a vehicle during a collision?

• The interaction between the car's force and the wall's force

• The energy created by the car's speed alone

• The damage is only caused by the wall

• The car's mass makes it break apart easily

Multiple Choice

Two identical cars are traveling in the same direction. One car is moving much faster than the other. If they both collide with identical walls, which car will likely have more damage and why?

• The faster car, because it has more energy

• The slower car, because it hits with less force

• Both cars will have the same amount of damage

• Damage is related to mass, not speed

The Engineering Design Process

• Engineers follow these steps to find effective solutions to various problems.

• It is an iterative process, involving repeating steps to refine the design.

• Key stages include defining the problem, developing solutions, and optimizing the design.

Multiple Choice

What is the primary goal of the engineering design process?

• To find effective solutions to problems.

• To conduct scientific experiments.

• To make products look visually appealing.

• To build things as quickly as possible.

Multiple Choice

Why is the engineering design process considered an 'iterative' process?

• It involves repeating steps to improve and refine the design.

• It must be completed in a single, linear sequence.

• It has a fixed number of steps that never change.

• It can only be performed by a single person.

Multiple Choice

An engineer creates a new water filter, but testing shows it doesn't work as well as expected. Based on the principles of the engineering design process, what should the engineer do next?

• Return to earlier steps to identify and fix the flaws in the design.

• Start over by defining a completely new problem.

• Sell the filter as-is since the process is complete.

• Conclude that the problem is impossible to solve.

​

​

Defining Criteria and Constraints

Criteria

• Criteria are the requirements that a design must meet to be considered successful.

• For a car's safety feature, a key criterion is its passenger survival rate.

• Another is how well the design reduces the force of an impact on passengers.

Constraints

• Constraints are the limitations or restrictions that the design must work within.

• The cost of materials is a common constraint that can affect design choices.

• Other constraints include the car's total weight or the time to develop the technology.

Multiple Choice

What is the primary role of criteria in the design process?

• To define the requirements for a successful design.

• To list the limitations or restrictions on a design.

• To determine the total cost and weight of a project.

• To outline the time available to develop a technology.

Multiple Choice

Why are the cost of materials and the total weight of a car considered constraints?

• Because they are limitations that the design must work within.

• Because they are requirements for the design to be successful.

• Because they measure the passenger survival rate.

• Because they reduce the force of an impact on passengers.

Multiple Choice

A design team wants to create the safest car possible with a very high passenger survival rate, but they have a very strict budget. Which statement best describes how the budget constraint might affect the safety criteria?

• The team may have to choose less effective materials to stay within the budget, potentially lowering the car's safety performance.

• The team will be able to ignore the budget to make sure the car is as safe as possible.

• The budget constraint will have no effect on the car's safety criteria.

• The budget constraint will force the team to increase the car's total weight.

​

​

Evaluating and Optimizing Solutions

• Engineers evaluate designs based on how well they meet criteria and constraints.

• Parts of different solutions can be combined to create an optimized design.

• For example, combining the best car safety features creates a safer vehicle.

Multiple Choice

What is the primary basis for engineers to evaluate a design solution?

• The project's specific criteria and constraints

• The personal preferences of the engineering team

• The novelty or newness of the design idea

• The materials that are easiest to find

Multiple Choice

Why would an engineer identify the strengths and weaknesses of competing design solutions?

• To prove that the first design was the best one all along

• To combine the strengths of different designs into a single, better solution

• To have more examples to include in a final report

• To select the design that is the least expensive to build

Multiple Choice

An engineer is developing a new bicycle. One design has a very strong frame but is too heavy. A second design is very lightweight but has a weak frame. Which of the following describes the best strategy for optimizing the bicycle design?

• Build the bike with the strong frame, because durability is most important.

• Build the bike with lightweight materials, because speed is most important.

• Combine the strong frame from the first bike with the lightweight materials from the second bike.

• Start over and design a completely different type of vehicle, like a scooter.

​

​

Modeling and Testing in Engineering

• Engineers use models like crash-test dummies with sensors to collect collision data.

• This testing process is iterative, meaning it is repeated to improve the design.

• Engineers analyze data to see how design changes can improve safety.

• For example, data may show a new crumple zone reduces forces on the dummy.

​

Multiple Choice

What is the main purpose of using models like crash-test dummies in engineering?

• To collect data from collisions to improve safety

• To make the car look more futuristic

• To see how fast the car can go

• To build the car as cheaply as possible

Multiple Choice

How does the iterative testing process help engineers?

• It is repeated to allow engineers to use data to make improvements to the design.

• It is only done once to confirm the first design is safe.

• It is repeated until the crash-test dummy breaks.

• It is only done at the very end of the building process.

Multiple Choice

After making a change to a car's crumple zone, engineers run a new test and the sensors on the dummy show lower force readings. What is the most logical conclusion?

• The new crumple zone successfully reduced the forces on the dummy.

• The sensors on the dummy are not working correctly.

• The car's design cannot be improved any further.

• Crash-test dummies are not useful for collecting data.

Car Safety: Crumple Zones and Safety Glass

​

Crumple Zones

• These are designed to absorb energy during a car crash by folding.

• They increase the time of impact, reducing force on the passengers inside.

• This helps prevent sudden stops and protects the body's internal organs.

​

Tempered Glass

• Used for a car's side and rear windows to prevent sharp injuries.

• It is specially designed to shatter into tiny, harmless pebble-like pieces.

• This prevents dangerous shards of glass from flying during an accident.

​

Laminated Glass

• Used for the front windshield to keep it from shattering completely.

• It has a strong plastic layer in the middle holding it together.

• If broken, the glass cracks in a weblike pattern instead of shattering.

Multiple Choice

What is the primary purpose of a car's crumple zone?

• To make the car look more modern and stylish.

• To absorb crash energy and reduce the force on passengers.

• To make the car lighter and more fuel-efficient.

• To prevent the car from making loud noises during a crash.

Multiple Choice

How does the way tempered glass breaks differ from how laminated glass breaks?

• Tempered glass is used for the windshield, while laminated glass is used for side windows.

• Tempered glass shatters into small, pebble-like pieces, while laminated glass cracks in a weblike pattern.

• Tempered glass has a plastic layer, while laminated glass is a single sheet of glass.

• Tempered glass is designed to be unbreakable, while laminated glass is designed to shatter easily.

Multiple Choice

After a front-end collision, a car's hood is folded and the windshield has a weblike crack but is still in one piece. What is the best conclusion that can be drawn about the car's safety features?

• The car's safety features have failed to work correctly.

• The crumple zone absorbed energy and the laminated windshield held together as designed.

• The tempered glass in the side windows must have also shattered.

• The car was not moving very fast at the time of the impact.

​

​

Car Safety: Air Bags and Seat Belts

Air Bags

• An air bag is a fabric safety bag that deploys automatically during a car collision.

• It inflates rapidly to create an energy-absorbing cushion between the passenger and the car's interior.

• This feature lengthens the passenger's stopping time to prevent injury and works best with seat belts.

Seat Belts

• Seat belts prevent passengers from being thrown from the vehicle or against the interior in a crash.

• They keep passengers correctly positioned, allowing other safety features like air bags to work effectively.

• According to Newton's first law, a seat belt applies the crucial outside force to stop you safely.

Multiple Choice

What is the primary purpose of an air bag?

• To provide a cushion that absorbs energy in a collision.

• To replace the need for a passenger to wear a seat belt.

• To keep the passenger from being thrown out of the car.

• To apply an outside force to the passenger based on Newton's law.

Multiple Choice

What is the relationship between seat belts and air bags during a collision?

• By keeping the passenger in the correct position for the air bag to work.

• By making the air bag inflate with more force.

• By signaling the air bag to deploy faster during a crash.

• By helping the air bag absorb more energy from the passenger.

Multiple Choice

Based on the information provided, which statement best explains how an air bag helps prevent injury in a crash?

• It increases the passenger's stopping time, which reduces the force of impact.

• It applies a strong outside force to stop the passenger instantly.

• It helps the seat belt lock in place more securely.

• It prevents the passenger from moving forward at all.

​

​

What Is a Concussion?

• A concussion is a mild brain injury from a blow to the head.

• Kinetic energy from the impact makes the brain move inside the skull.

• The brain collides with one side of the skull in a primary impact.

• It can then bounce, causing a secondary impact on the opposite side.

​

Multiple Choice

What is the definition of a concussion?

• A mild brain injury from a blow to the head

• A crack in the skull bone

• A bruise that appears on the skin

• A temporary feeling of sadness

Multiple Choice

What is the relationship between a blow to the head and the brain's movement during a concussion?

• The skull bones bend and press on the brain

• Kinetic energy from the impact causes the brain to move

• The brain rapidly grows in size

• Muscles in the neck pull on the brain

Multiple Choice

Based on the process of a concussion, what is a likely consequence of the brain's collision with one side of the skull?

• The brain immediately stops moving after the first impact

• The skull absorbs all the force, protecting the brain completely

• The brain can bounce and cause a second impact on the opposite side of the skull

• The primary impact is the only one that occurs in a concussion

​

​

Nature's Safety Designs

• A smaller brain has less mass, which means less force during an impact.

• The brain fits tightly inside the skull, which prevents it from moving around.

• Special tissues around the brain act like cushions to absorb impact forces.

• Beaks and horns are able to absorb the shock from a powerful impact.

​

Multiple Choice

What is the primary purpose of the natural safety designs found in animals?

• To reduce the force and absorb the shock from an impact

• To help an animal attack other animals more effectively

• To increase the size and mass of the animal's brain

• To allow the brain to move more freely within the skull

Multiple Choice

How does having a smaller brain contribute to an animal's safety during an impact?

• A smaller brain has less mass, which creates less force during a sudden stop.

• A smaller brain is harder and more resistant to damage.

• A smaller brain fits more loosely in the skull, allowing it to move.

• A smaller brain is cushioned by thicker protective tissues.

Multiple Choice

Which of the following animals would be best protected from brain injury during an impact, and why?

• An animal with a small brain that fits tightly in its skull.

• An animal with a large brain that fits loosely in its skull.

• An animal with a small brain that fits loosely in its skull.

• An animal with a large brain that fits tightly in its skull.

Helmet Technology

• Helmets have a hard outer shell to protect from sharp objects.

• Inner materials absorb the force of an impact.

• Special liners in modern helmets absorb more impact energy.

Multiple Choice

What is the main purpose of a helmet's design?

• To protect the head by blocking sharp objects and absorbing impacts.

• To make the wearer more visible to others.

• To keep the head warm and dry in bad weather.

• To be as lightweight and comfortable as possible.

Multiple Choice

What is the specific role of the inner materials and special liners inside a helmet?

• To absorb the energy from an impact.

• To make the helmet fit tightly on the head.

• To protect the head from sharp objects.

• To provide a surface for cooling vents.

Multiple Choice

A helmet is designed with a very hard outer shell but no inner foam or special liners. What would be the most likely outcome if this helmet were struck hard?

• The shell would stop sharp objects, but the force of the impact would still be dangerously transferred to the head.

• The helmet would provide complete protection from both sharp objects and the force of the impact.

• The hard outer shell would shatter, offering no protection at all.

• The helmet would be less effective against sharp objects but better at absorbing impact.

​

Common Misconceptions

Misconception	Correction
A perfect design can be created on the first try.	Engineering is an iterative process of testing and modification to improve a solution.
A car that doesn't look damaged is safe after a crash.	The car's crumple zone could be damaged, offering no future protection.
Air bags are all you need for safety in a car.	Air bags work with seat belts, which position you for protection.
You don't need a helmet for a short bike ride.	A serious head injury can happen at any speed or distance.

​

Summary

• Newton's Third Law states that collision forces are equal and opposite.

• The engineering design process creates solutions by defining criteria and testing models.

• Safety features like crumple zones and airbags increase impact time to reduce force.

• A concussion is a brain injury caused by the brain colliding with the skull.

Poll

On a scale of 1-4, how confident are you about the concepts covered in today's review?

• 1

• 2

• 3

• 4