6.5 Rolling

Describe the kinetic energy of a system that has translational and rotational motion.

• The total kinetic energy of a system is the sum of the system’s translational and rotational kinetic energies. Relevant equation:. KKtott =+ rans Krot

Describe the motion of a system that is rolling without slipping.

• While rolling without slipping, the translational motion of a system’s center of mass is related to the rotational motion of the system itself with the equations:
• For ideal cases, rolling without slipping implies that the frictional force does not dissipate any energy from the rolling system.

Describe the motion of a system that is rolling while slipping. BOUNDARY STATEMENT Rolling friction is beyond the scope of AP Physics 1. BOUNDARY STATEMENT The precise mathematical relationships between linear and angular quantities while a rigid body is rolling while slipping are beyond the scope of AP Physics 1 and 2, and students will not be expected to model those relationships quantitatively. However, students are expected to qualitatively explain the changes to linear and angular quantities while a rigid body is rolling while slipping. AP Physics 1: Algebra-Based Course and Exam Description Energy and Momentum of Rotating Systems UNIT 6 TOPIC 6.6 Motion of Orbiting Satellites

• When slipping, the motion of a system’s center of mass and the system’s rotational motion cannot be directly related.
• When a rotating system is slipping relative to another surface, the point of application of the force of kinetic friction exerted on the system moves with respect to the surface, so the force of kinetic friction will dissipate energy from the system.