Suppose that, while lying on a beach near the equator of a far-off planet watching the sun set over a calm ocean, you start a stopwatch just as the top of the sun disappears. you then stand, elevating your eyes by a height h = 1.43 m, and stop the watch when the top of the sun again disappears. if the elapsed time is it = 11.9 s, what is the radius r of the planet to two significant figures? notice that duration of a solar day at the far-off planet is the same that is on earth.

R=3818Km

Explanation:

Take a look at the picture. Point A is when you start the stopwatch. Then you stand, the planet rotates an angle α and you are standing at point B.

Since you travel 2π radians in 24H, the angle can be calculated as:

 t being expressed in hours.

From the triangle formed by A,B and the center of the planet, we know that:

 Solving for r, we get:

report!

explanation:

physics means: "the branch of science concerned with the nature and properties of matter and energy. the subject matter of physics, distinguished from that of chemistry and biology, includes mechanics, heat, light and other radiation, sound, electricity, magnetism, and the structure of atoms."