Centripetal Force and Circular Motion
Any object moving in a circle constantly changes direction → it is constantly accelerating → requires a net force directed toward the center.
Centripetal force: F_c = mv²/r. Increases with the square of velocity. Decreases with a larger radius.
Provided by: string tension (ball on string), friction (car turning), gravity (satellite orbit), normal force (banked curve).
Centrifugal "force": The apparent outward feeling in a turning car. This is not a real force — it is the result of inertia resisting the change in direction. In an inertial (non-rotating) reference frame, you simply tend to continue straight while the car turns.