Transcript How bad was it? - UNL | Transportation Systems Engineering

How bad can it be?
Learning Objective: To use a software call
Logger Pro to determine the impact force
during a collision.
Presentation at the Math and Science Summer Technology Institute
Summer 2009 – Omaha Site
Mid America
Transportation
Center
Nebraska
Engineering
Learning Objectives:
• To use a software call Logger Pro to
determine the impact force during a
collision.
• To introduce the biomechanical limits the
body can withstand in a collision
• To introduce the engineering in car and
roadside designs that reduce the
probability of a fatal impact
What is the science behind the toy?
• The center object will appear and
disappear if you move the toy vertically
quickly because it has more mass than the
outer shell of the toy.
Inertia – the resistance to change in motion of an object
How do they design a car to overcome the passengers inertia?
How does a force impact inertia?
A force is any push or pull on an object.
When a force is applied to an object, it can cause
an object to accelerate.
This is Newton’s Second Law.
How are cars or roadsides designed to lesson the impact forces?
How to use Logger Pro to
determine a cars velocity
Open logger pro
Click on Insert
Click on Movie
Choose “” Movie from the desktop
Play the movie
Set the scale using the yellow ruler.
Set the origin using the X/Y button with dot.
Use the point plotter to track the location of the vehicle
before and after the impact.
Change the position vs time graph to a velocity vs time
graph by clicking on the y axis labels.
Use the slope finder “m” button to determine the slope of
the velocity vs time graph, or the acceleration of the
object.
So how much can we take?
Applied force (g’s)
Biomechanical Damage
10
Black out
30-35
Ribs Broken
70-75
Blunt Force Truama
88
Cracked Skull
120
Head Seperation
These values taken from: (Euro NCAP)
ASSESSMENT PROTOCOL AND BIOMECHANICAL LIMITS
So where do we go from here?
• Shopping for a safer car.
• Improving Highway Safety
Post Activity Questions
1.
2.
3.
4.
5.
6.
In you own words describe what is meant by inertia.
When riding in moving car, what safety device(s) are
designed to overcome inertia?
Describe how we determined the car’s momentum in
the video clip.
What was the force called that caused a change in
momentum?
If your in a car travelling at 26 m/s (60 mph) and you
weigh 100 kilograms, how much momentum do you
have?
If your airbag slows you down in .1s,what force is
applied to your body? How many “g’s” is this?
How bad can it be?
Learning Objective: To use a software call
Logger Pro to determine the impact force
during a collision.
Presentation at the Math and Science Summer Technology Institute
Summer 2009 – Omaha Site
Mid America
Transportation
Center
Nebraska
Engineering