As Shown in the Figure, a 0 $19 \mathrm {~N} / \mathrm { m }$

As shown in the figure, a 0.23-kg ball is suspended from a string 6.87 m long and is pulled slightly to the left. As the ball swings through the lowest part of its motion it encounters a spring attached to the wall. The spring pushes against the ball and eventually the ball is returned to its original starting position. Find the time for one complete cycle of this motion if the spring constant (force constant)is $19 \mathrm {~N} / \mathrm { m }$ (Assume that once the pendulum ball hits the spring there is no effect due to the vertical movement of the ball.)