A rigid sphere of radius $R_S$ made from a material with specific gravity $SG_s$ is completely submerged in a tank of water with radius $R_t$ and initial depth $L$ as shown in the figure
The sphere is placed over a small hole of radius a in the bottom of the tank that is open to the atmosphere.
Find an inequality were the sphere will remain sitting on the bottom of the tank plugging the hole. You may assume that $a<< R_S$
How do I begin to solve this? Can someone point me in the right direction?