Which term describes a force toward the center of rotation?

Which term describes a force toward the center of rotation?

• A. Centrifugal force
• B. Centripetal force
• C. Rolling friction
• D. Static friction

Answer: (B)

The force toward the center of rotation is centripetal force. In circular motion, the direction of velocity is always changing toward the center, which requires an acceleration toward that center with magnitude a = v^2/r. The centripetal force is the net inward force that provides this acceleration and can arise from tension, gravity, the normal force, or friction, depending on the situation. It isn’t a separate kind of force on its own; it’s the label for the inward resultant of the real forces acting on the object. In a rotating frame, you might hear about centrifugal force, which appears outward, but in an inertial frame the inward centripetal force is the actual cause of the circular motion. Rolling friction and static friction refer to other contact forces and don’t specifically describe the inward pull toward the rotation center.

The force toward the center of rotation is centripetal force. In circular motion, the direction of velocity is always changing toward the center, which requires an acceleration toward that center with magnitude a = v^2/r. The centripetal force is the net inward force that provides this acceleration and can arise from tension, gravity, the normal force, or friction, depending on the situation. It isn’t a separate kind of force on its own; it’s the label for the inward resultant of the real forces acting on the object. In a rotating frame, you might hear about centrifugal force, which appears outward, but in an inertial frame the inward centripetal force is the actual cause of the circular motion. Rolling friction and static friction refer to other contact forces and don’t specifically describe the inward pull toward the rotation center.