A uniform solid cylinder of mass 1.5 kg and radius 0.12 m is released on a horizontal…
PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Energy and Momentum of Rotating Systems · Energy and Momentum of Rotating Systems
Problem
A uniform solid cylinder of mass 1.5 kg and radius 0.12 m is released on a horizontal surface with an initial center-of-mass speed of 3.0 m/s and no initial rotation. The surface is rough enough to prevent it from remaining in pure translation, but not so rough that it immediately sticks.
Answer the following questions qualitatively—no numerical calculations are required.
(a) Describe the direction of the kinetic-friction force acting on the cylinder immediately after it is released, and explain your reasoning in terms of the motion of the point of contact.
(b) Explain how the translational speed of the cylinder changes while slipping persists.
(c) Explain how the angular speed of the cylinder changes during the same interval.
(d) State the condition that signals the transition from slipping to pure rolling and describe how an observer could recognize when that transition has occurred.
(e) Discuss the forms of energy present before release, while the cylinder is slipping, and once pure rolling is achieved. Account for any difference between the initial and final mechanical energies of the system.