What is a practical method to verify CG calculations on a worksheet?

• A. Recalculate using each weight and arm, recompute total weight and total moment, then compare the resulting CG to the calculated CG.
• B. Just trust the initial numbers
• C. Only check the total weight
• D. Use the average of all moments

Answer: (A)

Verifying CG calculations comes from doing an independent cross-check of the whole worksheet. The CG is found from the total moment divided by the total weight, so you verify by recomputing both totals and then the CG itself and comparing to the value shown.

To do this, take every item on the worksheet, multiply its weight by its arm to get that item’s moment, and sum all those moments. Sum all the weights to get the total weight. Then compute the recomputed CG as total moment divided by total weight. If this recalculated CG matches the value on the worksheet, the distribution and math are consistent; if not, you’ve caught an entry or calculation error, such as a wrong weight, a wrong arm, or a missing item.

Why not trust the initial numbers or just check the total weight? Because CG depends on how weight is distributed, not just how much there is total. A worksheet can have the correct total weight but an inconsistent moment or CG if any item is mis-entered. Averaging moments isn’t a valid method for CG, since CG is a ratio, not an average of moments.