If the total weight increases but total moment stays the same, what happens to CG?

• A. CG increases
• B. CG decreases
• C. CG stays the same
• D. CG becomes zero

Answer: (B)

Center of gravity is the balance point where all weight effectively acts, and it’s found from CG = total moment / total weight. If you raise the total weight but keep the total moment unchanged, that ratio must get smaller, so the CG moves closer to the reference datum.

For example, if the total moment is 1000 in-lb and the weight is 1000 lb, the CG is 1.0 in from the datum. If the weight increases to 1200 lb while the moment stays at 1000 in-lb, the CG becomes 1000/1200 ≈ 0.83 in. The CG has decreased.

The other possibilities don’t fit: CG staying the same would require the moment to increase proportionally with weight; CG becoming zero would require the moment to be zero.