nevermind on the first one, i wasn't taking into consideration the length of the rope plus the ball for the denominator.
Can anyone point me in the right direction for the second one?
A tether ball leans against the post to which it is attached. The string is attached to the ball such that a line along the string passes through the center of the ball. The string to which the ball is attached has length 1.50 m and the ball's radius is 0.105 m and has a mass of 0.266 kg ...