A Day in the Life of John Henry, A Traffic Cop

Written by Barbara Duch. 1993, Revised 1995.

At 13:20 on the last friday in September, 1989 a frantic call was received at the local police station. There had been a serious automobile accident at the intersection of Main Street and State Street, with injuries involved. Lt. John Henry arrived at the scene 10 minutes after the phone call and found that two cars had collided at the intersection. In one car, the driver was unconscious and in the other car both driver and one passenger were injured.

After the emergency vehicles transported the injured to the hospital, Lt. Henry's responsibility is to investigate the accident in order to determine whether one of the drivers (or both) are responsible. With the severity of injury in this accident, the investigation is critical because there may be a fatality involved.

What questions does John Henry have to answer in this investigation? What measurements does he need to take? What data should he collect? What other information does he need to record in order to aid the investigation? What physics principles will John Henry need to use in order to help analyze the data and answer his questions?

If two cars moving at right angles to each other collide, in what direction do you expect the cars to be moving after the collision?

What factors will influence the direction and distance traveled after impact?

Go to Page 2 (and sketch), Page 3, Page 4. To to Instructor's Objectives

Online Resources

Accident Reconstruction Resources by Custom Design and Consultation
Links related to Accident Investigation by National Association of Investigative Specialists
Related Links by Texas Association of Accident Reconstruction Specialists
Accident Reconstruction by Renfroe Engineering
Car Resources from the Escape! series on PBS

Last updated Feb. 23, 1999.
Copyright Barbara Duch, Univ. of Delaware, 1993.