A thin disk of mass 0.150 kg slides across a level
PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Energy and Momentum of Rotating Systems · Energy and Momentum of Rotating Systems
Problem
A thin disk of mass 0.150 kg slides across a level, nearly friction-free surface. At a particular instant its position vector measured from the origin is r=(−0.60m)^ and its velocity is 4.0 m s⁻¹ directed 30∘ above the –x-axis.
Treat the disk as a point particle.
(a) Calculate the magnitude of the disk’s angular momentum about the origin at this instant. Express your answer with the appropriate units.
(b) A short time later the speed of the disk is still 4.0 m s⁻¹, but its velocity is perpendicular to its position vector while the magnitude of the position vector remains 0.60 m. Determine the new magnitude of its angular momentum and state the factor by which the magnitude has changed compared with part (a).