40 
20 
20 
40 
l(c x)? +(H*)? ] 1/2 
Sen carta [(o*)* +(H*)"] 
8000 
6000 
4000 
2000 
- 2000 
- 4000 
- 6000 
- 8000 
Fig,9. Variation of the envelope, the average potential energy, and the phase of the 
crests for relatively large values of x: as a function of ft 
-97— 
