937 
-3- 
we shall treat the shock wave in water as a wave of finite amolitude ana neylect the Irreversible 
heating at the shock front. 
A shock wave in water of intensity po, and particle velocity vy strikes normally on the 
alr water Interface. Immediately afterwards tne cressure and particle velocity at the interface 
are o. and v, wnile a shock wave of intensity co, ang carticle velocity v, has set out Intc the 
air. The law cf propagation cf tne quantity > then gives us 
AG 5 Up a UC) Ss ah (1) 
In shock waves the carticle velocity immediately behind the front is a function of 
pressure so that we have two further relations 
dy (0,) (2) 
d, (c,) (3) 
where © ana ty are the aporooriate functions for water and air resoactively. 4, (0) and f(o) 
for water have been comruten by Senney and Dasgucta and tabulated C » For air ano for pressures 
not exceeding about six atmosoheres ¢,(c) \s the well known Hugoniot formula which has been 
tabulated by Taylor 3), With the aia of these tables ana equations (1), (2) and (3) the values 
of Dy and v, may be found for a given value On* Table 1 shows the results together with , and 
Us the velocities cf the shock waves in water | and air ressectively. The tadle was constructsa 
assuming a temperature of 20°C, ana a pressure of one atmosohere. Pressures are absolute, not 
excess over one atmosonerc. 
Pa 
atmospheres 
Comparison with eri t. 
If the water velocity Vv, or the Intensity or velocity of tne air shock wave Is known then 
Table 1 enables us to determine. the Intensity y of the shock wave in water. A Curve has been 
given showing the velocity with which the water Surface moves when @ No. 8 dstonator is exologed 
beneath It at deotns from one to elyht inches. The present caper contains a recoro Figure 4 
from which the velocity of the transmitted shock wave can oe obtained when the detonator is ata 
depth of one inch. Measurement of this record gives the following figures. 
Distance cf wave from water surface he tt de 
Velocity of nave in fu secon ra oer (Sea a ea 
The intensity of the shock wave in water froma No. 8 detonator basco on the water surface 
velocities is shown in Figure 5. It falls off mucn more rapidly than the reciorocal of the 
distance sees. 
