## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (3rd Edition)

Let $M_s$ be the mass of the sun. Let $R$ be Jupiter's orbital radius. We can write an expression for the period of Jupiter's orbit. $T = \sqrt{\frac{4\pi^2~R^3}{G~M_s}}$ Since the period does not depend on the mass of the object in orbit, any object with the orbital radius of $R$ around the sun would have the same period. Therefore, the earth would also have a period of 11.9 years. The correct answer is (c) 11.9 years.