Final answer:
The time taken by the carousel to complete one rotation about its x-axis is 40 seconds.
Step-by-step explanation:
The question you've asked pertains to the time taken by a carousel to complete one rotation about its x-axis. According to the details provided, the carousel with 20 horses completes one full rotation every 40 seconds. Therefore, the time taken by the carousel to complete one rotation about its x-axis is 40 seconds. This is a straightforward instance of measuring rotational motion or uniform circular motion, where the rotational period is given directly