448 
2K 
1+ fir dak Kio] ”* 
W,= 14+0(2Z,-U/2Z, 
Ko) = (2,-Y/ez, +1) yg) 
y 9) a log Z/Z, -# (Vz, -/Z) t(z"- 1/242 , 
eek t 7/2t) + Lost + (esa )ay 2, 
is + i/o, ) = B42 ee. Ce ao/t, B, , 
Eqs. 7.5 suffice to determine x as a function of q for given initial 
A= 
(7.5) 
values of 2) : oF >» and G A After (2 ; Oo, » and Oo have been 
determined for a given explosive, x is convemiently determined as a 
function of R/a, by first calculating it as a function of q by Eq. 7.5 
for several appropriate values of q, plotting or tabulating these values 
of x against xq (equal to R/a, by Eq. 7.4) and interpolating from the 
graph or table to obtain x for a desired value of R/a,. 
To calculate the time-spread parameter A » we employ 
Eq. 5.23 and tks ea ga by xX. 
- Z ME Za) 
Lewin Be as [lg F eaaeonlee 
LEM ae + Ey ME (fara. 
Eq. 7.6 determines the parameter ¥ as a function of q and x(q). Jt is 
convenient to calculate for those values of q employed in the calcula- 
tion of x(q), and to plot or tabulate the resulting values of Yr against 
Xq. From such a graph or table one may at once interpolate g for a de- 
sired value of R/a,- We remark that at large values of R/a,, the last 
term of Eq. 7.6 is the dominant one in Y « it contains as a factor 
a or 6,/8, » where @, is ao/eos Thus at large distances the time of 
decay, Y@ » is controlled by 9,, a time characteristic of water rather 
than of the explosive, although of course the second factor in this term 
61 
