A small block of mass m slides down from the top of a frictionless inclined surface, while the inclined plane is moving towards left with constant…

A small block of mass $\displaystyle m$ slides down from the top of a frictionless inclined surface, while the inclined plane is moving towards left with constant acceleration $\displaystyle a_0$. The angle between the inclined plane and ground is $\displaystyle \theta$ and its base length is $\displaystyle L$. Assuming that initially the small block is at the top of the inclined plane, the time it takes to reach the lowest point of the inclined plane is $\displaystyle \_\_\_\_$.