91 105 



In dealing with water it Is convenient to choose p^ = 0. The adla- 

 batlc for water that passes through a pressure of one atmosphere and a tem- 

 perature of 20 degrees centigrade is given by Penney and Dasgupta (24) as 

 v{p + 3)°-'3* = ^ .666, where v Is in cubic centimeters per gram and the unit 

 for p is 10^ kilograms per square centimeter. With the help of the binomial 

 expansion and Equation [l8l] it is easily found that the equivalent series In 

 s, when p is in pounds per square inch, is 



p = 309000s (1 + U.12s + 23. 6s^- • •) 



or, approximately, if s is replaced by p/309000 in the s^ term, 



p = 309000s (l + Jcqqq) pounds per square inch [l8U] 



Comparison with [l8l]. in which p^ is now 0, shows that p^Cq = 309,000, b^ = 

 U.12poCo' = 1.273 X 10«. 



Hence [l83] for the pressure on the wall may be written, for water, 

 when the incident pressure p. is in pounds per square inch, if p^ = 0, 



= 2p. ( 



1 + ^' ) [185] 



150000' 



