Question

Which is correct about the Earth-Sun system?
Newton's Laws determined rules to describe the motion of objects orbiting the Sun.
Kepler's laws identified the force shaping Earth's orbit.
The sun is at one focus of the Earth's elliptical orbit
The Earth stays the same distance from the Sun throughout its orbit.

Answer 1

Correct statements: 1 and 3.

Brief explanations:
- Newton's laws determined rules to describe the motion of objects orbiting the Sun — True. Newton’s laws plus universal gravitation explain and predict orbital motion and reproduce Kepler’s laws.
- Kepler's laws identified the force shaping Earth's orbit — False. Kepler’s laws describe how planets move (empirical laws) but do not identify the underlying force; Newton later showed gravity is that force.
- The Sun is at one focus of the Earth's elliptical orbit — True. Planetary orbits are ellipses with the central mass at one focus (for Earth–Sun the Sun is essentially at that focus).
- The Earth stays the same distance from the Sun throughout its orbit — False. Earth’s distance varies (perihelion ≈147.1 million km, aphelion ≈152.1 million km; orbital eccentricity ≈0.0167).