A planet orbits a star once every 3.05x10^7 s in a nearly circular orbit of radius 1.44x10^11 m. (a) With respect to the star, determine the angular...

A planet orbits a star once every 3.05x10^7 s in a nearly circular orbit of radius 1.44x10^11 m.(a) With respect to the star, determine the angular speed of the planet. (Your answer is correct)(b) With respect to the star, determine the tangential speed of the planet.(Your answer is correct)(c) With respect to the star, determine the magnitude and direction of the planet's centripetal acceleration. (Answer: .00598, incorrect)I was able to get the first two questions but for some reason I can't get the third. My answer was .00598 toward the center of orbit but it keeps saying that it's incorrect (toward the center of orbit is correct). Any ideas?