A centrifugal pump runs at \(1750 \mathrm{rpm}\) while pumping water at a rate of \(50 \mathrm{~L} / \mathrm{s}\). The water enters axially, and leaves tangential to the impeller blades. The impeller exit diameter and width are \(300 \mathrm{~mm}\) and \(10 \mathrm{~mm}\), respectively. If the pump requires \(45 \mathrm{~kW}\) and is 75 percent efficient, estimate the exit angle of the impeller blades.