I did the Foucault pendulum experiment today. I used a 45 pound weight hung on about 12 or 15 feet of inelastic cord. I understand that a great and highly precise experiment will show one full rotation of the plane of oscillation in about 24 hours, but my pendulum was rotating at a rate that appears to be too fast.
What would be the causes of too fast rotation? The Earth's rotation must impart a torque on the weight through the twisting of the cord, can that increase rotation speed? Here is my main question: can I trust the underlying signal of the counterclockwise rotation even though it is going too fast? Is this experiment sufficient to show that I am in the southern hemisphere? What might cause the too fast rotation? I released the pendulum by burning its restraint cord, and you can see the initial motion is very nearly planar with little to no elliptical deviation. How can I improve my experiment? I will get some metal wire today and replace the nylon cord with metal wire for a repeat experiment. Please criticize my experiment to help me diagnose the systematics which lead to the too fast rotation. The time elapsed in the gif is about 6 minutes.