For the arrangement shown in the figure, Area of the cross section of the tankA=5m2 and area of the orifice a = 4 cm2. If the time interval in seconds after which the water jet ceases to cross the wall is Nx103 sec. The value of N is ________. [Assume that the container remaining fixed]

For vertical motion, 1=12gt2 t=15sTo just cross the wall, velocity of efflux should be v= 2gh where, h is the level of water above the oriffice. In horizontal direction, x=2gh15=2h ⇒h=x24=0.25m (i.e. level goes down from 0.81m to 0.25m .   Using equation of continuity) -5⋅dhdt=2gh4×10−4 on solving t=1000s