Chapter 2, Problem 1SP

A railroad engine moves forward along a straight section of track for a distance of 70 m due west at a constant speed of 5 m/s. It then reverses its direction and trawls 32 m due east at a constant speed of 4 m/s. The time required for this deceleration and reversal is very short due to the small speeds involved.

1. a. What is the time required for the entire process?
2. b. Sketch a graph of average speed versus time for this process. Show the deceleration and reacceleration upon reversal as occurring over a very short time interval.
3. c. Using negative values of velocity to represent reversed motion, sketch a graph of velocity versus time for the engine (see fig. 2.15).
4. d. Sketch a graph of acceleration versus time for the engine (see fig. 2.16).