## Calculation of required quantity of magnesium
import math
j = 15. ## current density in mA m**-2
m = 0.0243 ## molar mass of magnesium
F = 96490. ## farad charge
n = 2. ## charge on ion
t = 10. ## time in years
print("\n Example 13.2")
a = m*j*1e-3*(t*365.*24.*3600.)/(n*F)
print'%s %.2f %s '%("\n Amount of magnesium required is ",a," kg m^-2")