2007-03-01 18:06:11 · 6 answers · asked by mysteri0_mask 1 in Science & Mathematics ➔ Biology
If earths curvature of its surface is 7.98 inches per mile. How can we see a boat that is 20 feet high go over the horizon and dissapear if that boat would have to be about 30 miles away to be able to see it dissapear. *btw my math might be off*
2007-03-01 18:29:05 · update #1
In case you haven't been told, the earth is not flat. You can see only as far as you can see and no farther.
2007-03-01 18:14:24 · answer #1 · answered by Anonymous · 0⤊ 0⤋
More to your question, you must also take into account the height of the object you are watching, as well as the height of your eyes about the ground or sea.
Here's a link to a page with a full explanation and a formula for calculating the distance to the horizon.
If you're standing in a boat and your eyes are nine feet above the water, then the horizon appears to be about 3.51 nautical miles (or 4.04 regular miles) away.
http://www.boatsafe.com/nauticalknowhow/distance.htm
http://www.boatsafe.com/nauticalknowhow/miles.htm
2007-03-02 02:22:35 · answer #2 · answered by BP 7 · 1⤊ 0⤋
BP has it right.........and using the formula in the link he provided, you get that a person with an eye 6 feet above sea level would lose sight of a 20 foot tall boat at 6.44 miles........which, having sailed about 20,000 ocean miles, sounds just about right.
2007-03-05 07:32:41 · answer #3 · answered by yankee_sailor 7 · 0⤊ 0⤋
Dear Friend
You can if you have a perfect vision see upto a max of 10kms at sea level, its that simple
2007-03-02 02:23:41 · answer #4 · answered by kartik 2 · 0⤊ 0⤋
on flat plane we can see at a distance of eight kilometer. because after that we can see but not clearly due to polution
2007-03-02 02:19:05 · answer #5 · answered by RAJU 1 · 0⤊ 0⤋
i have heard and studied that the far point of a normal human eye is infinity.
2007-03-02 04:49:00 · answer #6 · answered by ikkie 2 · 0⤊ 0⤋