119 



W 2 Poo 3 8 Poo J 



2 TTP ~ ^ p ^Kiax " 'S "a- a 



i.e., when a a 2 fimax (13) 



This naxlmim value of (12) Is 



2 Pa, V^ -^ -'/^, -^^ P V- 



7 ~ Smax (2 - 2 ) s 2 r^ a„^3, 



Insertion of this into (11) gives 



laaximian impulse „ 'i z. -^ nA\ 



of pressure ■=" "- %ax iP^^oo '•^^' 



