You are standing on a beach looking out into the ocean. Assuming your view is unobstructed, how far can you see?

(In reply to Solution by Steve Herman)

As I recall, one quarter of the earth's circumference is 10 million meters, so in kilometers, R=40,000/2*pi.  A fairly tall person would have eyes 2 meters above the ground, so we get sqrt(.004*40000/2*pi)=5.04 kilometers (between 3 and 4 miles). As a check, the earth's circumference is about 25,000 miles, so the radius R is about 3979 miles or 21 million feet.  Multiplying  by 2*6 feet gives 253 million and taking the square root gives 15,878 feet or 3 miles.

I hope I finally got this right. Originally I was using 2R for R.

Edited on January 23, 2005, 5:11 pm

Posted by Richard on 2005-01-23 16:41:51