13.4 Exercise 15

The Sun orbits the Milky Way galaxy once each $2.60 \times 10^{8} \text{years}$, with a roughly circular orbit averaging a radius of $3.00 \times 10^{4}$ light-years. (A light-year is the distance traveled by light in 1 year.) Calculate the centripetal acceleration of the Sun in its galactic orbit. Does your result support the contention that a nearly inertial frame of reference can be located at the Sun? (b) Calculate the average speed of the Sun in its galactic orbit. Does the answer surprise you?