Find the discharge over a rectangular notch of width $4$m$.$ The head of water over the notch is $0\mathrm{.}2$ m$.$ The velocity of approach is given as $0\mathrm{.}1$m$/$s$.$ Take Cd$=0\mathrm{.}6.($b$)$ A sharp edged circular orifice of diameter $7\mathrm{.}5$ mm is provided in a tank containing water to a height of $1\mathrm{.}2$m above the orifice. The jet strikes a wall $1$:$25$ m away and $0\mathrm{.}35$ m vertically below the centreline of the orifice. Actual discharge of water is measured to be $40$ kgof water collected in $5$ minutes. Calculate the orifice coefficients