By lifting the barrier, you start the "race of balls"!
The balls have positional energy at the start, what gradually turns into kinetic energy.
The balls start from the same height, this is why their speed by the end of their route will be the same, but time needed to pass the route will not!
The larger the pitch of the slope, the more speed is gained by the object.
The positional energy at the start is used by ski jumpers, who are able to jump more than 200 meters from a 185 meters high cliff.
