An exoplanet named Boreas-4 is orbited by two of its major moons, Boreas-4b and Boreas-4c, in coplanar circular orbits. Boreas-4b has an average orbital radius of 1.50 × 104 km and completes one full orbit in 12.5 days12.5\text{ days}12.5 days. Boreas-4c is located at an average orbital radius of 3.84 × 104 km from the center of the planet. Assuming Kepler's third law of planetary motion applies, what is the orbital period of Boreas-4c?
23.4 days23.4\text{ days}23.4 days
32.0 days32.0\text{ days}32.0 days
51.2 days51.2\text{ days}51.2 days
81.9 days81.9\text{ days}81.9 days
31 exam-style questions on OCR A A Level Physics Gravitational fields, covering Point and spherical masses, Newton's law of gravitation, Planetary motion, and Gravitational potential and energy. Each one has a worked solution and a mark scheme showing where the marks go.