Which statement best describes the center of mass?

Which statement best describes the center of mass?

• A. The point where gravity acts
• B. The point around which the mass is distributed
• C. The geometric center of the object
• D. The point of zero velocity

Answer: (B)

Center of mass is the balance point where the entire mass of a body or system can be considered to be concentrated. Its location depends on how mass is distributed throughout the object: if density is uniform, it sits at the geometric center, but for irregular shapes or uneven densities it shifts toward heavier regions. In a uniform gravitational field, the weight acts as if it is applied at this single point, which is why this point is used to describe how the body will move or balance. The description that it’s the point around which the mass is distributed captures this idea of distribution determining the location. The other statements don’t fit because gravity acts on all parts of the body (not just at one point except as a simplifying model), the COM isn’t necessarily the geometric center, and it isn’t defined by zero velocity.

Center of mass is the balance point where the entire mass of a body or system can be considered to be concentrated. Its location depends on how mass is distributed throughout the object: if density is uniform, it sits at the geometric center, but for irregular shapes or uneven densities it shifts toward heavier regions. In a uniform gravitational field, the weight acts as if it is applied at this single point, which is why this point is used to describe how the body will move or balance. The description that it’s the point around which the mass is distributed captures this idea of distribution determining the location. The other statements don’t fit because gravity acts on all parts of the body (not just at one point except as a simplifying model), the COM isn’t necessarily the geometric center, and it isn’t defined by zero velocity.