The bifilar-type pendulum shown in Figure is used as a centrifugal pendulum to eliminate torsional oscillations. The U-shaped weight fits loosely and rolls on two pins
of diameter d2 within two larger holes of equal diameters d1 With respect to the crank, the counterweight has a motion of curvilinear translation with each point moving in a circular path of radius r = d1 - d2. Prove that the U-shaped weight does indeed move in a circular path of r = d1 - d2.