9. A 10-kg block slides down a smooth inclined surface as shown in Fig. 2. Determine the terminal velocity of the block if the 0.1 mm gap between the block and the surface contains SAE 30 oil at 60 °F. Assume the velocity distribution in the gap is linear, and the area of the block in contact with the oil is 0.1 m² Fig. 2. 0.1 mm gap 20°