The discussion revolves around the forces involved when a car brakes, specifically focusing on the work done by these forces. The subject area includes concepts from mechanics, particularly the roles of friction and normal forces in relation to motion.
The discussion is active, with participants providing insights and questioning assumptions about the forces at play during braking. Some guidance has been offered regarding the role of kinetic friction, but there remains uncertainty about the definitions and implications of static versus kinetic friction.
Participants are navigating the complexities of friction types and their effects on work done during braking, indicating a need for clarity on these fundamental concepts.
okgo said:When a car brakes, isn't it in motion and using kinetic friction to stop, and not static friction?
Static friction causes rolling motion in wheels, but there is no rolling motion so it skids. So shouldn't kinetic friction do work and not static? I'm a bit confused on the two concept.