Ball rolling down a hill using diameter

[pogo2065]

Hello everyone!

I am new here, so im not sure how things normally work.

anyways, on the the problem.

I have a ramp made out of channeling, approximately 8 foot long, that i am going to roll spherical objects down. i want to find out the theoretical time it will take. friction doesnt matter since the channeling is going to be positioned in a way that the balls will rool down on two thin "lines" of channeling. if you need ill post a picture later when im at home.

i believe it reduces to a vector problem, but its been a while (6+ months) since ive done vectors.

If you need any more information just ask and ill provide you with it.

Thanks!