In 1851 Jean Bernard Leon Foucault Demonstrated the Rotation of the Earth

Multiple Choice

In 1851 Jean Bernard Leon Foucault demonstrated the rotation of the earth using a pendulum 11.0 m long,which was set up in the Paris Observatory.How long would it have taken for Foucault's pendulum to make one complete swing back to its starting point if g = 9.81 m/s² at the observatory?

A) 6.65 s
B) 5.63 s
C) 1.79 s
D) 2.12 s
E) 2.58 s