327 



IJ > (10) 



In some instances it may be more convenient to express the second integral 

 of (8) in the form 



- ^5,a4*^^a.'x;^-^>;t-rVc.), 



(11) 



where 



r* 



= (r^^r'*-Xrr.'t^ 4,' )''''-, (12) 



For use in subsequent applicaticxis, we list several special forms 

 of (8). For rso , we get 



(13) 



Suppose "T is a characteristic time for the deformation process. If 

 c^t >> R. ,we obtain to a good approximation. 



If '^o«Cot <&; R, , we get 



2. Cavitation 



In the initial stages of the impact between the plate and the 

 explosion wave, large negative pressures may under some circumstances 

 develop at the surface of the plate due to the reflected rarefaction wave. 

 Since water, especially dirty water, cannot support a tension of great 



18 



