9. (12 points) As shown in the figure, $A$ and $B$ are the two endpoints of a diameter of a circular track. Three miniature robots, Jia, Yi, and Bing, start moving simultaneously on the circular track at a uniform speed. Jia and Yi start from $A$, and Bing starts from $B$; Yi moves clockwise, while Jia and Bing move counterclockwise. After 12 seconds, Jia reaches $B$, and after another 9 seconds, Jia catches up with Bing for the first time, which is also when Jia meets Yi for the first time; when Bing first reaches $A$, it will take another $\qquad$ seconds for Yi to reach $B$ for the first time.
9. (12 points) As shown in the figure, $A$ and $B$ are the two endpoints of a diameter of a circular track. Three miniature robots, Jia, Yi, and Bing, start moving simultaneously on the circular track at a uniform speed. Jia and Yi start from $A$, and Bing starts from $B$; Yi moves clockwise, while Jia and Bing move counterclockwise. After 12 seconds, Jia reaches $B$, and after another 9 seconds, Jia catches up with Bing for the first time, which is also when Jia meets Yi for the first time; then, when Bing first reaches $A$, how many more seconds will it take for Yi to reach $B$ for the first time?

【Solution】Solution: Jia takes 12 seconds to travel from $A$ to $B$, and then after another 9 seconds, Jia reaches point $C$, where the length of $BC$ is $\frac{3}{4}$ of the length of $AB$. Therefore, the length of $AC$ is $\frac{1}{4}$ of the length of $AB$. In 21 seconds, Jia's distance traveled is $AB + BC = \frac{7}{4} AB$, Yi's distance traveled is $AC = \frac{1}{4} AB$, and Bing's distance traveled is $BC = \frac{3}{4} AB$. Thus, the speed ratio of Jia: Yi: Bing is $7: 1: 3$. The time it takes for Bing to travel from $C$ to $A$ is $21 \times \frac{1}{3} = 7$ seconds. At this time, Yi travels from $C$ to point $D$ in 7 seconds as well. Since $CA = \frac{1}{3} BC$, then $CD = \frac{1}{3} AC$, and $CB = 8 CD$. After Bing reaches $A$, the time it takes for Yi to reach $B$ is $8 \times 7 = 56$ seconds. Therefore, the answer is: 56