As the device is placed at an angle, the damping increases as
shown by the ringdown waveforms. Stepping from 15◦ angle to
30◦ angle, the friction force (Fd) approximately doubles. In theory,
the friction force is proportional to the sine of the angle. Therefore,
this doubling in friction force makes mathematical sense, because
for 15◦, the sin(15) is 0.26 and for 30◦, the sin(30) is 0.5, meaning
that the force should approximately double when moving from a
15◦ to 30◦ angle