The rectangular tank is filled with heavy oil (like glycerin) at the bottom and water at the

Question:

The rectangular tank is filled with heavy oil (like glycerin) at the bottom and water at the top, as shown in the figure. The tank is now moved to the right horizontally with a constant acceleration and ¼ of water is spilled out as a result from the back. Using geometrical considerations, determine how high the point A at the back of the tank on the oil-water interface will rise under this acceleration.