Distance is a scalar quantity that refers to "how much ground an object has covered" during its motion. Displacement is a vector quantity that refers to "how far out of place an object is"; it is the object's overall change in position.
Centripetal force is the force REQUIRED for circular motion. Centrifugal force is the force that makes something flee from the center.
Speed is the time rate at which an object is moving along a path, while velocity is the rate and direction of an object's movement.
Velocity is the rate of change of displacement. Acceleration is the rate of change of velocity.
