EXAMPLES. 181 



EXAMPLES. 



1. With what velocity will water issue from a small ori- 

 fice 64 feet below the surface of the liquid ? 



Ans. 64 feet. 



2. If 252 cubic inches of water flow in one second through 

 an opening of 6 square inches, find the head of water. 



Ans. 2.28 inches. 



3. If water flows from a vessel whose cross-section is 60 

 square inches, through a circular orifice in the bottom 

 5 inches in diameter under a head of water of 24 feet, find 

 its velocity. Ans. 41.58. 



4. A vessel, formed by the revolution of a semi-cubical 

 parabola about its axis, which is vertical, is filled with water 

 till the radius of its surface is equal to its height above the 

 vertex. Find the time of emptying the vessel through a 

 small orifice at the vertex. 



[Let aif = y? be the equation of the generating curve, 

 and Tc the area of the orifice.] 



Ans - raV? 



5. A conical vessel, the radius of whose base is r and alti- 

 tude h, is filled with water; the axis is vertical and the 

 water issues through an orifice in the vertex, of area Tc. 

 Find (1) the time in which the surface of the water will 

 descend through one-half its altitude, and (2) the time in 

 which the cone will empty itself. 



6. Find the time in which the cone in Ex. 5 would 

 empty itself through an orifice in its base. 



167rr 3 



Ans. 



/~h 



A/ H~ 



V 2g 



7. A sphere is filled with water. Find the time of empty- 

 ing it through an orifice in its bottom. IGrrr 2 



Ans. 



