Measurements of angle as a function of time in a physical pendulum driven at a fixed rotation rate

In these three runs, we record measurements of the angle of a pendulum driven at a constant angular frequency by a motor. Each run corresponds to a different configuration of the pendulum. In Run 3, the angle alpha is pi/2 rad; in Run 4, alpha = 0.85 +/- 0.03 rad; and in Run 5, alpha = 2.23 +/- 0.03 rad.All measurements begin with the motor switched off, so the initial angle is zero. Once the motor is turned on, the data show a rapid change in the angle, which can take either positive or negative values. After some time, the motor is switched off, and the angle returns to oscillating around zero with a decaying amplitude.To determine the equilibrium positions at different angular frequencies, we analyse the portion of the data recorded after the motor is turned on and the transient behaviour has decayed.The measured periods of the rotation for each run, along with their corresponding uncertainties, are:Run 3: T = [0.924;1.03;0.834;0.83;0.682;0.685;0.624;0.624;0.601;0.6;0.576;0.573;0.521;0.526;inf; 11.5;4.35;2.68;1.91;1.58;1.48;1.17;1.03;1.04] (seconds) and errT = [0.007;0.01;0.006;0.01;0.004;0.007;0.006; 0.003;0.006;0.005;0.004;0.003;0.005;0.004;0;0.6;0.03;0.01;0.02;0.01;0.01;0.02;0.01;0.02] (seconds).Run 4: T = [inf;4.25;2.59;1.96;1.488;1.37;1.2;1.145;1.012;0.957;0.894;0.9;0.85;0.833;0.776;0.785;0.757;0.735;0.705;0.701] (seconds) and errT = [0;0.05;0.01;0.02;0.007;0.02;0.008;0.007;0.008;0.005;0.007;0.006;0.006;0.005;0.003;0.003;0.006;0.004;0.004;0.003] (seconds).Run 5: T = [inf;13.4;4.4;2.64;1.89;1.5;1.22;1.02;0.877;0.773;0.734;0.696;0.69;0.663;0.665;0.618;0.620;0.562;0.575;0.534;0.53] (seconds) and errT = [0;0.6;0.1;0.04;0.02;0.02;0.002;0.01;0.008;0.009;0.007;0.006;0.003;0.006;0.003;0.005;0.004;0.005;0.005;0.003;0.003] (seconds).The periods and their uncertainties are listed in the same order as in the data files; thus, the first period in Run 4 corresponds to Run1_4.