Which statement is true about CG and weight?

• A. CG is the ratio of total moment to total weight
• B. CG is the ratio of total weight to total moment
• C. CG is the sum of the weights
• D. CG is the sum of the moments

Answer: (A)

Center of gravity is the balance point of the aircraft, found as the weighted average of all weight locations. In practice, you take the moment produced by each weight (weight times its distance from the datum) and sum them to get the total moment. The center of gravity is then this total moment divided by the total weight: CG = total moment / total weight. This ratio gives the distance from the datum to the CG.

Think of it like balancing a seesaw: the larger the moments on either side, the farther the balance point shifts. If you know all the weights and where they’re located, you can compute the CG by dividing the total moment by the total weight.

Why the other ideas aren’t correct: CG isn’t the sum of the weights (that would be total weight) and isn’t the sum of the moments (that’s total moment). It also isn’t the ratio of weight to moment (that would have the wrong units and meaning). The essential concept is the moment-weight ratio, yielding the CG location.