Centre of Mass in Pure Rolling – Rankers Physics

Calculation of Center of Mass: Practice Problem & Solution

Assertion (A): Centre of mass of a body in pure rolling on a horizontal surface always moves in a straight line. Reason (R): Centre of mass of a body must be inside the body.  
Both (A) & (R) are true and the (R) is the correct explanation of the (A)
Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(A) is true but (R) is false
Both (A) and (R) are false

Solution Explained:

To solve this problem, we apply the core principles of Calculation of Center of Mass. Understanding the underlying formula is key to arriving at the correct answer below:

Assertion (A) is true; the center of mass of a body in pure rolling on a horizontal surface moves along a straight line (rectilinear motion). Reason (R) is false; the center of mass can be outside the physical boundaries of the body (e.g., for a ring or a hollow sphere).

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