Question

according to keplers first law, the planets each move in an elliptical orbit with the sun...
a at the geometrical center.
b on the opposite side of the same ellipse.
c at one focus.
d at both foci.

Explanation:

Kepler's first law states that planets move in elliptical orbits with the Sun at one of the two foci of the ellipse. So we analyze each option:

• Option A: The geometric center of an ellipse is not where the Sun is (the center and foci are different in an ellipse), so A is wrong.
• Option B: The Sun is not on the opposite side of the ellipse from a focus - the Sun is at a focus, so B is wrong.
• Option C: According to Kepler's first law, the Sun is located at one focus of the elliptical orbit of a planet, so C is correct.
• Option D: The Sun is at only one focus (the other focus is empty in the case of planetary orbits around the Sun), so D is wrong.

Answer:

C. at one focus.