Calculating the moment of overturning can be accomplished by using a relatively complex equation and weighing method. The overturning moment is defined as the moment of energy needed to upset another object. In other words, this factor defines the energy needed to make an object unstable. For the purpose of this calculation, an object is considered "unstable" if it topples, falls over or otherwise experiences an unwanted change of direction or state that presumably causes inconvenience to that object.
Weigh the object and fixture you have chosen for the purpose of this calculation. Record the weight in terms of conventional or metric measurement.
Balance the object on its fixture in order to determine the object's centre of gravity. Use the tape measure to determine the distance between this centre of gravity and the bottom of the object.
Use Miles' equation to calculate the root mean square acceleration of the object.
Multiply the root mean square acceleration by the height of the centre of gravity of your object. Calculate the overturning moment by using the equation G * CG * 1W = OM, where G = root mean square acceleration, CG = centre of gravity distance and W = combined weight of the object and fixture.
Use a scientific calculator with multi-functionality, such as square roots and the quadratic formula, for the most accurate results. Use an object that is relatively lightweight in order to keep results manageable and small in value. Objects to be tested should be of moderate size in order to allow for accurate measurements using the tape measure.
Be sure to keep your calculations consistent with the same metric or conventional values, to further insure accuracy in your results.