Question

The centre of mass of a system of particles is at the origin. It follows that

Options

•  the number of particles to the right of the origin is equal to the number of particles to the left

•  the total mass of the particles to the right of the origin is same as the total mass to the left of the origin

• the number of particles on X-axis should be equal to the number of particles on Y-axis

•  if there is a particle on the positive X-axis, there must be at least one particle on the negative X-axis

• none of these

Answer 1

None .

The centre of mass of a system of particles depends on the product of individual masses and their distances from the origin.
Therefore, we may say about the given statements:
(a) Distance of particles from origin is not known.
(b) Masses are same but the distance of particles from the origin is not given.
(c) Distance of particles from origin is not given.
(d) It is not necessary that least one particle lies on the negative X-axis. The particles can be above the negative X-axis on X-Y plane.