Cylindrical vessel with a fluid rotates around the axis of symmetry with an angular velocity of w. Normally on a same horizontal level, pressure is same but here the pressure on the bottom near the vessel wall is more than the pressure at the center. Here ω = 5 rad/s, ℓ = 1m, r = 0.1 mm, R = 2 m.
                    
By the side wall of the vessel we tied a massless inextensible string of length ℓ. To this string we tie a balloon of radius r. During the rotation of the cylinder, the thread makes an angle a with the wall.