1507 
r2150 ft 
QA (source) (receiver) CS 
h-40 ft h,-40 ft 
Medium (1) 
C5 
Bt NOY BY" 
Medium (2) d 
C2, Cy 
Rigor ly 
Simple geometrical arrangement of source and receiver. 
c,= 5000 ft/sec 
¢G,* 1.15¢,= 5750 ft/sec 
angle of incidence, 9 = arc tan(75/40) = 61.93° 
critical angle 0.<are sin(1/1.15) 
Sess 
