Question

The centre of mass of a rigid body lies:

• A. inside the body
• B. outside the body
• C. neither (a) nor (b)
• D. either (a) or (b)

Hint:

For symmetric solid bodies, the centre of mass usually lies inside. For hollow or irregular shapes, it may lie outside the material of the body.

Answer 1

The Correct Option is D

Step 1: Recall the definition of centre of mass. The centre of mass is the point at which the entire mass of a body may be considered to be concentrated for the purpose of analyzing motion. Step 2: Understand possible locations. Depending on the shape and mass distribution of the body:

It may lie inside the body (e.g., solid sphere)
It may lie outside the body (e.g., ring, hollow sphere)
Step 3: Evaluate the options.

(A) Only inside — incorrect
(B) Only outside — incorrect
(C) Neither — incorrect
(D) Either inside or outside — correct ✔
Step 4: Final conclusion. The centre of mass of a rigid body may lie either inside or outside the body. \[ \boxed{\text{(D)}} \]