Analysis: Interpreting the tests

Although the two methods look quite different, in both cases the weight vector passes through the pivot so that its moment arm is zero.

This video explains in detail how this condition can be used to locate the centre of gravity.

Data from the experiment are given in the Downloads section below.

For most of the simple shapes used in the tests the location of the centre of gravity is obvious – it’s in the middle. The odd one out is the triangle, but it’s easily found from standard results. Knowing all this you can see how accurate the experimental results turned out to be.

Because the centre of gravity of a triangle often appears in engineering analysis, it’s worth learning as part of developing your engineers’ eyes.

Talking points

• What did you think of the agreement between the theoretical location of the centre of gravity of the triangle, and the data from tests?