A cylinder 8 in. in diameter and \(3 \mathrm{ft}\) long is concentric with a pipe of 8.25 in. i.d. Between cylinder and pipe there is an oil film. What force is required to move the cylinder along the pipe at a constant velocity of \(3 \mathrm{fps}\) ? The kinematic viscosity of the oil is \(0.006 \mathrm{ft}^{2} / \mathrm{s}\); the specific gravity is 0.92 .