Final answer:
To determine the number of revolutions the automobile tires make over 70,000 km, the total distance is divided by the circumference of a tire. The formula used is n = total distance traveled / (2πr), where r is the radius of the tire. Using the given measurements, the tires make approximately 240,632 revolutions.
Step-by-step explanation:
The question asks how many revolutions an automobile's tires make given a specific distance traveled and the tires' radius. This is a calculation involving the circumference of the tires and the total distance traveled. To find the number of revolutions (n), we use the formula n = total distance traveled / circumference of the tire. The circumference (C) is given by C = 2πr, where r is the radius of the tire. Given that the radius is 0.291 m and the car travels 70,000 km, which is 70,000,000 m, we calculate n as follows: n = 70,000,000 m / (2π * 0.291 m). Simplifying this, we get approximately 240,632 revolutions, which corresponds to option a).