Final answer:
The incorrect statement is (d) center of mass of a body is independent of the distribution of mass, as the center of mass actually relies on the mass distribution within the object.
Step-by-step explanation:
The incorrect statement among the following is (d) centre of mass of a body is independent of the distribution of mass. This statement is incorrect because the center of mass of a body indeed depends on how the mass is distributed within the object.
The other statements are correct: internal forces do not affect the motion of the center of mass of a system (a), the center of mass of a body lies towards the heavier side (b), and the center of mass may lie inside or outside of the material of the body (c).
In physics, especially when discussing mechanics and kinematics, these concepts are crucial. The center of mass provides a simplification for analyzing the motion of a system, where external forces play the primary role in changing its motion, supporting the principles laid out in Newton's laws of motion.