Two identical balls A and B each of mass 0.1 $kg$ are attached to two identical massless springs. The spring mass system is constrained to move inside a rigid smooth pipe bent in the form of circle as shown in the figure. The pipe is fixed in a horizontal plane. The centres of the balls can move in a circle of radius 0.06 $m$ . Each spring has a natural length of 0.06π m and force constant 0.1N/$m$. Initially both the balls are displaced by an angle θ=π/6 radian with respect to the diameter PQ of the circle and released from rest. The frequency of oscillation of the ball $B$ is