a ball i made, was simply created using box's some are rotated to become slopes.

i then created a path, i did this by using a line tool and created the direction on whihc the ball will travel.

once i had finished this, i then made a sphere (ball) and clicking animation...constraints...path constraints. clicked the line.

i changed the time line to 500 frames rather then 100, i also had to increase the speed to x4 as it was to slow.