A small steel bead slides without friction across a horizontal glass tabletop
PHYSICS · Multi-part · CBSE · Physics · System of Particles and Rotational Motion · System of Particles and Rotational Motion
Problem
A small steel bead slides without friction across a horizontal glass tabletop. The bead’s velocity is always directed strictly along the +x-axis of a fixed Cartesian coordinate system. At the instant shown, the bead is located at the point (0.25 m, +0.20 m). A second reference point, Q, is fixed on the tabletop at the coordinates (0.00 m, –0.40 m).
Treat the bead as a point particle.
(a) When the bead is at (0.25 m, +0.20 m), state whether its angular momentum, taken about the origin O, points into the page, out of the page, or is zero. Explain the reasoning that leads to your answer without performing any numerical calculation.
(b) Using the same qualitative reasoning, indicate the direction (into the page, out of the page, or zero) of the bead’s angular momentum when it is taken about point Q. Clearly justify your answer.
(c) Compare the magnitudes of the angular momenta in parts (a) and (b). State which is larger, or whether they are equal, and provide a brief explanation based on the geometry of the situation.