How do I apply a force to the other object in a collision?

I'm really new at this. Right now I have a sphere that is bouncing around in a flat level.

I've used materials to keep the sphere from losing energy if it hits the floor, but now I would like to add a section of floor that if the sphere lands on top of, will add force to the sphere in the upwards direction.

Is there a script I could add to the specific section of floor that basically says "if an object collides with me, add force to that object in the upwards direction."

More info:

-The section of floor is currently a box collider.

-The sphere is a sphere collider and a rigidbody.

After a bit of googling I came across something like this (I messed around with the 1700 to just try to see if it wasn't enough force):

function OnCollisionEnter(collision : Collision) {
    if (collision.rigidbody) {
        collision.rigidbody.AddForce (Vector3.up * 1700);
    }
}

but it doesn't work when I put the code on the floor section. Would you be able to explain how to do what I want and why the above code doesn't work?

Thanks.

Try submitting ForceMode.Impulse as the second argument to AddForce(). (As your code is now, you're only applying the force over one update - or maybe even no updates, although I'm not sure about that - which is unlikely to have any noticeable effect.)