The tangential acceleration of a cart moving at a constant speed in a horizontal circle is
(1) 0.0 m/s2
(2) 9.8 m/s2 in the direction of the velocity
(3) constant in magnitude and directed radially
toward the center of curvature
(4) constant in magnitude and directed radially
away from the center of curvature

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.