Five objects of mass m move at velocity at a distance r from an axis of rotation perpendicular to the page through point A, as shown below. The one that has zero angular momentum about that axis is

Question

Five objects of mass m move at velocity  at a distance r from an axis of rotation perpendicular to the page through point A, as shown below. The one that has zero angular momentum about that axis is

Quizplus · Accepted Answer

The angular momentum of an object of mass m moving at velocity v at a distance r from an axis of rotation perpendicular to the page through point A is given by L = mvr. Since all objects have the same mass, velocity, and distance from the axis of rotation, the only factor that could make the angular momentum zero is the angle between the velocity vector and the line connecting the object to the axis of rotation. In option D, the velocity vector is parallel to the line connecting the object to the axis of rotation, which means that the angle between them is zero and the angular momentum is zero. Therefore, option D is the correct choice.

Five Objects of Mass M Move at Velocity at a Distance