PHYSICS · Multi-part · CBSE · Physics · System of Particles and Rotational Motion · System of Particles and Rotational Motion
Problem
In a classroom demonstration, a marble rolls toward the center of a puck that is initially at rest on a frictionless horizontal table. The puck can both translate and rotate freely. A student claims that the angular momentum of the marble–puck system calculated about an axis through the puck’s center will be conserved during the collision, even though the puck is free to move.
(a) Identify any external forces that exert a torque about an axis through the puck’s center during the collision.
(b) Explain whether angular momentum about that axis is conserved for the system during the impact, and justify your reasoning.