A gold pendulum swings with angular acceleration a, and a point on the edge has tangential acceleration a. A silver pendulum swings with angular acceleration 3a, and a point on the edge has tangential acceleration 5a. How does the radius of the gold pendulum r gold compare with the silver pendulum r silver ? A 1/15
B 5/3
C 15
D 3/5​

The space between two 15-in.-long concentric cylinders is filled with glycerin (viscosity = 8.5 × 10-3 lb·s/ft2). the inner cylinder has a radius of 1 in. and the gap width between cylinders is 0.1 in. determine (a) the torque and (b) the power required to rotate the inner cylinder at 180 rev/min. the outer cylinder is fixed. assume the velocity distribution in the gap to be linear.