In this activity you will:
• Evaluate from simulated
collisions, the effect of rear-
end collisions on the neck
• Understand the causes of
• Understand Newton’s Second
Law of Motion.
• Understand the role of safety
devices in preventing whiplash
The Rear-End Collision
What Do You Think?
Whiplash is a serious injury that is caused by
a rear-end collision. It is the focus of many
lawsuits, loss of ability to work, and discomfort.
• What is whiplash?
• Why is it more prominent in rear-end collisions?
Record your ideas about these questions in your Active
Physics log. Be prepared to discuss your responses with your
small group and the class.
Coordinated Science for the 21st Century
Activity 8 The Rear-End Collision
For You To Do
1. You will use two pieces of wood to represent the torso (the
trunk of the body) and the head of a passenger. Attach a
small piece of wood (about 1" x 2" x 2") to a larger piece of
wood (about 1" x 3" x 10") with some duct tape acting like a
hinge between the two pieces.
a) Make a sketch to show your passenger. Label what each
part of the model passenger represents.
2. Set up a ramp against a stack of books about 40 cm high, as
shown in the diagram below. Place the wooden model
passenger at the front of a collision cart positioned about
50 cm from the end of the ramp. Release a second cart from
a few centimeters up the ramp.
a) In your log record what happens to the head and torso of
the wooden model.
3. With the first cart still positioned about 50 cm from the end
of the ramp, release the second cart from the top of the ramp.
a) Describe what happens to the head of the model passenger
in this collision.
b) Use Newton’s First Law of Motion to explain your
4. The duct tape represents the neck muscles and bones of the
vertebral column. How large a force do the neck muscles exert
to keep the head from flying