* Friction: Rough surfaces have more friction. Friction is a force that opposes motion between two surfaces in contact. The more uneven the surface, the more points of contact there are, and the greater the friction.
* Work: To overcome friction and move an object, you need to do work. Work is defined as force applied over a distance. Since rough surfaces require more force to overcome friction, more work is needed to move an object the same distance.
Example: Imagine pushing a heavy box across a smooth wooden floor versus pushing it across a carpet with a thick pile. You'll feel the difference! You'll need to push much harder on the carpet because the friction is greater.
