I am performing an experiment where a steel ball of diameter 7.5 mm is dropped by hand on an aluminised kapton foil. Four piezoelectric sensors are placed 55 mm away from the edges at a 45 degree angle and they measure the change in strain of the material from the drop and convert it to electrical signals, which can be measured using a picoscope. The set-up can be seen in the image above.
I do not understand if I am measuring the longitudinal waves, transverse waves or a mix of both here. How do I find which wave I am measuring?
My thoughts were that since the drop is perpendicular to the foil, I am measuring the transverse waves, but I am not sure. Any help in understanding would be appreciated.