This is meant to be physics
a ball moves along a smooth metal surface while an identical ball moves along concrete.
which surface exerts a smaller amount of frictional force on the ball?
1. neither concrete nor metal exert any friction on the ball because these two surfaces never result in a frictional force on any object.
2. the metal surface exerts less frictional force because there are fewer bumps and irregularities on it than there are on the concrete.
3. the concrete and metal surfaces exert the same amount of frictional force on the ball because they are both solid surfaces.
4. the concrete surface exerts less frictional force on the ball because there are fewer bumps and irregularities on the concrete than there are on the metal.