EXAMPLES 173 



~~ " ~~ seconds, 



and taking C = *593 determine the time of lowering the surface level of 

 a tank of 500 square feet sectional area from a depth of T5 feet to 1*0 

 feet above the vertex of the notch. 



Answer, t = 60 seconds. 



(6) Find the time required to empty a swimming bath through a flat 

 grating in the bottom of the deep end. 



Depth of water at deep end = 6 feet. 

 shallow end = 3 feet. 



Length of bath = 80 feet. 



Breadth = 30 feet. 



Area of grating = 2 square feet. Coefficient of discharge '65. 

 Answer. 596 seconds. 



(7) Two cylindrical tanks A (5 feet diameter) and B (10 feet diameter) 

 are connected by a short pipe 4 inches diameter with bell-mouth inlet. 

 At the beginning the level in A is 10 feet and in B is one foot above the 

 centre line of the pipe. In what time will the surface levels be the 

 same ? 



Answer. 188 seconds. 



