Coast Guard Exams
Question 805Navigation General70% to pass

If you count 20 seconds between seeing lightning and hearing the thunder, how far is the storm away from you?

AI Explanation
The correct answer is B) 4 miles. The relationship between the time it takes to hear thunder after seeing lightning and the distance to the storm is based on the speed of sound. Sound travels at approximately 1,100 feet per second, which means it takes about 5 seconds for sound to travel 1 mile. Therefore, if you count 20 seconds between seeing lightning and hearing the thunder, the storm is approximately 4 miles away (20 seconds / 5 seconds per mile = 4 miles). The other options are incorrect because 2 miles (10 seconds) is too close, 6 miles (30 seconds) is too far, and 8 miles (40 seconds) is also too far for the 20-second time interval observed.

Ready to test your knowledge?