EXAMPLES. 241 



5-inch pipe for 800 feet more, and a 4-inch pipe for the 

 remaining 1500 feet. The coefficient of friction / being 

 0.024, find (1) the diameter of a uniform pipe 3100 feet 

 long having the same friction, and (2) the velocity of dis- 

 charge. 



Use (7) of Art. 104 for v. 



Ans. (1) 4.427 inches ; (2) 4874 feet. 



27. If in the last example the first pipe of the main is 

 2000 feet long and 6 inches in diameter, the second 800 

 feet long and 5 inches in diameter, and the third 300 feet 

 long and 4 inches in diameter, the head being 75 feet, find 

 (1) the diameter of the equivalent main, and (2) the velocity 

 of discharge. Ans. (1) 5.2 inches ; (2) 5.289 feet. 



28. If in Ex. 26 the pipe is 6 inches in diameter for the 

 whole length of 3100 feet, the head being 75 feet, find the 

 velocity of discharge. Ans. 5.675 feet. 



29. Into a branch main 2000 feet long, 6 inches in diam- 

 eter, water enters with a velocity of 15.27 feet a second; 1 

 cubic foot of water is delivered into service-pipes for every 

 1000 feet of length,/ = .0303, what is the loss of head in 

 the 2000 feet ? Ans. 211.53 feet. 



