$10\mathrm{.}6\mathrm{.}15$ An engineering laboratory experiment uses a triangular weir in an open channel to measure florate. The nominal weir angle is $90\backslash$deg $.$ In a certain test, the head of water above the weir was $4$ in$.$ The uncertainty in the weir angle is $+2\backslash$deg and the uncertainty in the depth measurement is $0\mathrm{.}05$ in$.$ Compute the flowrate and the uncertainty in the flowrate. $($Ans $=0\mathrm{.}163$ ft$^3/$sec$)$