EXAMPLES. 183 



a square foot and the coefficient of efflux is 0.615, how 

 many cubic feet of water will be discharged per minute ? 



Ans. 118.695. 



16. A basin has in it a hole an inch square ; water in the 

 basin is kept at a constant level of 9 feet above the hole. 

 How many cubic feet of water will flow out in 1 hour, the 

 coefficient of efflux being 0.6 ? Ans. 360. 



17. A cylindrical vessel filled with water is 4 feet high 

 and 1 square foot in cross-section, and a hole of 1 square 

 inch is made in the bottom. If the coefficient of efflux is 

 0.6, in what time will f of the water be discharged ? 



Ans. 60 seconds, nearly. 



18. A cylinder, the area of whose cross-section is 60 sq. 

 ft, is filled with water to a depth of 12 feet ; a small hole is 

 made in its bottom, whose area is 0.5 square inches. In how 

 long a time will the depth of the water be (1) 8 feet and (2) 

 4 feet? Ans. (1) 45.8 minutes; (2) 105.4 minutes. 



19. The horizontal section of a cylindrical vessel is 100 

 square inches, its altitude is 3G inches, and the area of its 

 orifice is 0.1 of a square inch. If filled with water, in what 

 time will it empty itself, the coefficient of efflux being 

 0.62 ? Ans. 11 m. 36.5 s. 



20. What is the discharge per second through a rectangu- 

 lar orifice 2 feet wide and 1 foot high, when the surface of 

 the water is 15 feet above the upper edge, the coefficient of 

 efflux being 0.611 ? Ans. 38.6 cubic feet. 



21. What is the discharge per second through a rectan- 

 gular orifice whose height is 8 inches and whose width is 

 2 inches, under a head of water of 15 inches above the upper 

 edge, the coefficient of efflux being 0.628 ? 



Ans. 0.705 cubic feet. 



22. If the height of the rectangular orifice is 15 inches, 

 its width 25 inches, and the head of water is 4 inches 

 above the upper edge, what is the discharge per second, the 

 coefficient of efflux being 0.594? Ans. 12.19 cubic feet. 



