-25- 271 



We have shown that the impulse carried by the secondary- 

 pulse Is practically independent of the linear momentum s 

 of the bubble, and is given by (2. 32). 



The impulse carried by the primary shock wave is experi- 

 mentally measured to be" 



w2/3 

 ■^shock ~ '-^ ~~E — atmoHTjhore-seconds. 



A coniparison with (2.32) indicates that the impulse carried 

 by the secondary pulse is three times the impulse carried by 

 the shock wave. 



This conclusion can be stated in an approximate manner 

 in terms of the dxirations of the pulses. Using the relation 

 between the peak pressures obtained at the end of the last 

 section, one can state that the secondary pulse lasts about 

 eighteen times as long as the shock wave. 



This result, and formula (2.32), should not be taken 

 too literally but merely as order of magnitude statements. 

 The reason for this is that the impulse carried by the secondary 

 pulse was computed between the times when the pressure is zero. 

 This Includes a relatively long period of time during which 

 the pressure is low, and the resulting contribution to the 

 Impulse will not be experimentally noticed and will not have 

 much effect In damaging structures. 



* [3], p. 13 



