A uniformly dense 50 cm rod with a total mass of 0.2 kg is standing perfectly vertically on a horizontal surface. When given a slight (i.e., negligible) push the rod begins to topple over. Let's assume that static friction is sufficient to allow the rod to fall over without slipping at the base. What is the magnitude of the angular acceleration of the rod (in rad/s2) when it is at 30° relative to the vertical axis?