#Chapter 14,Example 1, page 453
#Determine the time to crest
I = 400 # mH of inductance
L = 500*10**-3 # mH
C = 1.5*10**-6 # micro F
from math import pi,sqrt
f = 1/(2*pi*sqrt(L*C))
t = 10**6/(4*f) # calulation done in the text is wrong
print"\n f1 = Hz",f
print"\n Time to crest = micro seconds",round(t)