Physics

As shown in the figure, a person starts running from a distance of from the right edge of a platform with a constant acceleration towards the edge. After leaving the platform, the person lands exactly at the center of the bottom of a truck's carriage. The vertical height from the right edge of the platform to the bottom of the truck's carriage is , and the horizontal distance from the edge of the platform to the center of the carriage is . Assuming , what is the initial velocity of the person when they leave the platform?