The sun orbits the center of the milky way galaxy once each 2.60 x 108 years, with a roughly circular orbit averaging 3.00 x 104 light years in radius. (a light year is the distance traveled by light in 1 y) part (a) calculate the centripetal acceleration of the sun in its galactic orbit in m/s2 numerica numeric value is expected and not an expression. part (b) calculate the average speed of the sun in its galactic orbit in m/s. numeric : a numeric value is expected and not an expression.