how far is the horizon ( sea level and 100m)?

Answer 1

It depends on what you are looking at.

If you are looking at the ground, then the distance is around 3 miles but it depends on your height.

BUT, somethings are quite tall and can be seen from a lot further. For example, on a clear day you can see the White Cliffs of DDiver from Calais which is abuot 26 miles away, that's becuase the cliffs are very tall.

See website below:
http://www.boatsafe.com/tools/horizon.htm

Answer 2

If your height above the surface (land or water) is zero, the distance to the horizon is also zero.

For heights that are small compared to the radius of the earth, imagine the line of sight from your eye to the horizon: this line is a tangent and will be perpendicular to a radius drawn to the earth's center. You now have a very skinny right triangle with one side equal to the earth's radius (R), the other equal to the distance to the horizon (d), and the hypoteneuse equal to earth's radius + your height (R+h).

(R+h)^2 = R^2 + d^2

R^2 + 2Rh + h^2 = R^2 + d^2

2Rh + h^2 = d^2

d = sqrt (2Rh + h^2)

But remember that R is huge compared to h, and if R = 6371 km, h must be in the same units, so h = 0.1 km and h^2 = 0.01 km, which can be ignored if h is small enough.

Then:
d = sqrt (2Rh) = sqrt (2*6371 * 0.1) = sqrt (1274) = 35.69 km.

For a person like me whose eyes are 6 feet above the ground, and an earth radius of 3959 miles, my horizon will be at sqrt (2*3959*6/5280) = sqrt(8.998) = 3.000 miles.

These answers ignore atmospheric distortion, which will allow you to actually see somewhat farther than the computed distances.

Answer 3

On a sparkling day you will locate 5 miles to the horizon. At that element you will see a sailboat as hull down, or merely see the mast above the water point. the respond extremely relies upon on how some distance off the water you're. At water point this is the miles. as much as the crows nest or different great shape it will boost critically

Answer 4

There's an equation for this...
D = 1.17 x square root of H
'D' is distance to the horizon, 'H' is height above the local surface.
So if you're 100m above sea level the horizon will be about 11.7 nautical miles away. At 10,000m it will be about 117 nautical miles away.

Answer 5

3.5 miles is in the back of my brain.
Sorry, my trig is not up to figuring out the from 100m bit.

Answer 6

I believe I learned in school ? the plain that you see ahead is roughly 50 miles,then the curviture falls out of site

Answer 7

Here are some formulae you can use.

http://en.wikipedia.org/wiki/Horizon

Answer 8

you would assume, that if you are at sea level, and so is the area infront of you, that the horizan is at 0m, i.e straigh infront of you

by you i mean the looking device, i.e the centre of your eye

Answer 9

About three to four miles - nearer then you think. It is correct - all sailors know this