Run some Physical Experiments.

1. Repeat questions 1 and 2 from the previous page. In repeating question 1, use frequencies from 1 Hz to about 12 Hz. Are these measured mode shapes mass-orthogonal?
2. Use the measured natural frequencies, the known mass, and the analysis given in Figure 6 in order to determine the interstory-stiffness.

Data analysis using the response to random loading is an advanced topic for seniors or graduate students.