97, 98.] IMPACT OF STREAM ON A LAMINA. 107 



the axis of abscissao, which may of course be regarded as a circle 

 of infinite radius. The rule of Art. 95 then gives 



/?-i AJw + B 



Fig. 9. 



U) 



To determine the constants, we have the conditions 



(a) f = i, for &amp;lt;f) = + x , 



(&) = x , for w = ; 

 to which we add 



(c) f=+ 1, for w=l. 



The last assumption fixes the breadth of the lamina in terms of the 

 unit of length. Of these conditions (a) gives A = (7, (6) gives 

 BD, and (c) makes ^1 = B*. Hence (63) becomes 



1-^w? 





If ifr = 0, and &amp;lt; lie between + 1, the right-hand side of (64) is 



* That is, we assume \ ic = + 1 when f = + 1, and therefore \ w= - 1 for = - 1. 

 The alternative supposition leads to the same results. 



