PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Energy and Momentum of Rotating Systems · Energy and Momentum of Rotating Systems
Problem
During a classroom demonstration, a physics teacher rolls a uniform solid cylinder of mass M and radius R across a horizontal table at a constant translational speed. The teacher tells students that the total mechanical energy of the cylinder is entirely kinetic.
Answer the following qualitatively, using clear, concise physics reasoning supported by appropriate vocabulary. Numerical calculations are NOT required.
(a) Describe the two distinct forms of kinetic energy that the cylinder possesses while it rolls without slipping. In your description, identify the type of motion associated with each form and the location in the object to which each form is most directly linked.
(b) Two identical solid cylinders are moving across identical horizontal surfaces. Cylinder A rolls without slipping at a speed of 3ms−1, while Cylinder B slides without rotating at the same speed. Explain which cylinder has the greater total kinetic energy and justify your answer without performing a numerical calculation.
(c) Suppose a third cylinder, identical in mass to Cylinder A but of larger radius, rolls without slipping across the table with the same angular speed as Cylinder A. Qualitatively describe how its total kinetic energy compares with that of Cylinder A and explain your reasoning.