Foucault pendulum sharing the rotation of the earth about its own axis, the suspension point of the pendulum traces out a circular path during one sidereal day. At the latitude of Paris, 48 degrees 51 minutes north, a full precession cycle takes just under 32 hours, so after one sidereal day, when the Earth is back in the same orientation as one sidereal day before, the oscillation plane has turned by just over 270 degrees. If the plane of swing was north-south at the outset, it is east-west one sidereal day later. This also implies that there has been exchange of momentum;
Paraconical pendulum about its vertical axis as well as swinging in two perpendicular directions. Therefore a paraconical pendulum has three degrees of freedom. When the rotation of the Earth is taken into account, the formal equations in classical mechanics of the behavior of this dynamical system are rather complex. The rolling friction of the ball upon the flat is extremely low, so that a paraconical pendulum has a high Q factor, principally determined by air resistance. Typically a paraconical pendulum is built as a solid body with a stiff rod, rather than with a flexible wire or cord, and its length is