1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution If I consider an arc shaped element of the liquid, then the physical forces acting on it are 4 different tensions , normal force and gravitational force on it. Two of the tensions would be acting along tangential direction (opposite to each other) and the other two along radial direction(opposite to each other) . Now, in steady state, normal force and gravitational force cancels each other. I assume that in dynamic state, too, normal force and gravitational force cancel each other. Assuming tangential acceleration to be 0, the two opposite tensions along tangential direction cancel each other. Now, wrt. inertial frame , the two opposite radial tensions provide centripetal acceleration. But then how to decide the shape?