Chapter 2, Problem 26PQ

Scientists and engineers must interpret problems from various sources. We can practice this skill anytime we read a newspaper or magazine or browse the Internet. Consider the “Rocket Car” urban legend that can be found on many Internet sites, in which the Arizona Highway Patrol allegedly found the vaporized wreckage of an automobile. The story goes that after some analysis and investigation, it was believed that a former Air Force Sergeant attached solid-fuel rockets to his 1967 Chevy Impala and ignited the rockets approximately 3.9 miles from the crash site. The vehicle quickly reached a speed of approximately 275 mph. It continued at this speed for 20 to 25 seconds. The car remained on the highway for 2.6 miles before the driver applied the brakes. The brakes melted and the tires blew out, causing the vehicle to become airborne. It traveled through the air for 1.3 miles before it hit a cliff face 125 feet above the road. Of course, this story was debunked. It is physically implausible, but it can still provide an opportunity to practice analyzing a problem.

1. a. C Draw a Sketch of the Situation.
2. b. C For the constant-velocity part of the car’s motion, identify initial and final positions, the velocity, and the time interval.
3. c. N Calculate the displacement using the position data and then again using the velocity and time data. Are your results consistent?
4. d. C If your results are not consistent, reread the legend and identify possible sources of the discrepancy.