2-69. The tapered settling tank is filled with oil. Determine the resultant force the oil exerts on the trapezoidal clean-out plate located at its end. How far from the oil

surface does this force act on the plate? Use the integration method.Take Po900 kg/m³. F_{R}=\int_{A} p d A=\int_{y 1}^{y 2} \rho g y(2 x d y) \frac{y-2.5}{x-1.25}=\frac{4-2.5}{0.5-1.25} ; \quad 2 x=5-y