$4(30\%)-$ Referring to the pipe U$-$bend shown below, it is connected to a flow system by flexible hoses that transmit no force. The cross$-$sectional area of the pipe is $1sq.$ in$.$ and the flowing fluid is water. Pressure at points $1$ and $2$ are $20$ psig and $18$ psig respectively. The horizontal component of the support force, neglecting the weight of the fluid and the pipe, is $50lbf.$ Calculate the water flow rate in cu$.ft./$s$.$