The orbit of the planet Venus is nearly circular with an orbital Velocity of 126.5 x 10^3 km/h. Knowing that the mean distance from the center of the sun to center of Venus is 108x 10^6 KM and that the radius of the sun is 695.5 x 10^3km determine (a) the mass of the Sun. (b) the acceleration of gravity at the surface of the sun.