A person is standing at the edge of the water and looking out at the ocean. The height of the person's eyes above the water is h= 1.6 meters, and the radius of the earth is R= 6.38 *10^6 meters. (a) How far is it to the horizon? (b) Express (a) in miles.

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I hate these types of problems in physics, because I never know how to approach them.