Static friction is the friction between an object at rest and the surface on which it is resting on.
Kinetic friction is the friction between a moving object and the surface on which it moves.
Hopefully you understood and this helps :)
An inclined plane, just like all simple machines, makes work easier. I think it is a type of simple machines. Therefore, I think the best answer is A.
The medicine ball wall hit the ground faster, if that makes sense to you
