According to Kepler's third law of planetary motion, the square of the orbital period of a planet is directly proportional to which power of the semi-major axis of its elliptical orbit?

💡 Solution & Explanation

Kepler's harmonic law states that the square of the time period of revolution of a planet is proportional to the cube of the semi-major axis of its elliptical path around the sun. This relationship allowed Isaac Newton to subsequently derive his universal law of gravitation. The constancy of this ratio applies to all bodies orbiting a central mass.