Final answer:
The car's odometer should be reported in miles. It measures total distance traveled, not displacement, and when used with time, it calculates average speed, not velocity, unless motion is in a straight line and unidirectional.
Step-by-step explanation:
The most appropriate way to report the distance driven using the car's odometer, which measures to the nearest 0.1 miles, is in miles. Odometers record the total distance traveled, not displacement.
When you divide the total distance traveled on a car trip by the time for the trip, you are calculating the average speed. The magnitude of the average velocity is the same as the average speed only when the motion is in a straight line in a single direction.
Understanding Speedometers and Odometers
A car's speedometer measures the instantaneous speed, not velocity, as it does not provide information about the direction of motion. A car speedometer with a 5.0% uncertainty reading 90 km/h has a range of possible speeds from 85.5 km/h to 94.5 km/h. Converting this range to miles per hour, you get approximately 53.11 mi/h to 58.75 mi/h (using the conversion factor 1 km = 0.6214 mi).