The centre of mass of a rigid body lies-

The correct answer is option 4) i.e. either inside or outside the body

CONCEPT:

• Center of mass: Center of the mass of a body is the weighted average position of all the parts of the body with respect to mass.
  • The centre of mass is used in representing irregular objects as point masses for ease of calculation.
  • For simple-shaped objects, its centre of mass lies at the centroid.
  • For irregular shapes, the centre of mass is found by the vector addition of the weighted position vectors.

EXPLANATION:

• The location of the centre of mass depends on two factors - the shape of the body and the distribution of the mass.
• The centre of mass can lie inside the body when the object is solid.
• In the case of a circular ring, the centre of mass lies at its geometric centre which is a point outside its body.
• Since the centre of mass is a point where the whole mass of the system appears to be concentrated, it is not necessary that this point should be inside the body.
• So, the centre of mass of a body can be either inside or outside the body.