A flat block is pulled along a horizontal flat surface by a horizontal rope perpendicular to one of the sides. The block measures \(1.0 \mathrm{~m} \times 1.0 \mathrm{~m}\), has a mass of \(100 \mathrm{~kg}\) and a constant velocity of \(1.0 \mathrm{~m} / \mathrm{s}\), and is separated from the flat surface by a \(0.10-\mathrm{cm}-\) thick oil layer of \(15{ }^{\circ} \mathrm{C}\) SAE 20 crankcase oil. Find the coefficient of sliding friction for the block. Does this coefficient of friction change with the velocity?