Question: what is the magnitude of earth's centripetal acceleration as it orbits the sun?
Answer: Assume that the Earth's orbit is a circle of radius 1.50 x 1011 m. Then a = 4π2 (1.5x1011m)/(31558464 s)2 = 0.005946 m/s2 = . 0059 m/s/s toward the Sun.