The sled shown in Fig. P1.76 slides along on a thin horizontal layer of water between the ice and the runners. The horizontal force that the water puts on the runners is equal to \(1.2 \mathrm{lb}\) when the sled's speed is \(50 \mathrm{ft} / \mathrm{s}\). The total area of both runners in contact with the water is \(0.08 \mathrm{ft}^{2}\), and the viscosity of the water is \(3.5 \times 10^{-5} \mathrm{lb} \cdot \mathrm{s} / \mathrm{ft}^{2}\). Determine the thickness of the water layer under the runners. Assume a linear velocity distribution in the water layer.

Figure P1.76