//example-17.4
//page no-526
//given
//one mole of magnesium weighs
MMg=0.0243  //Kg
//current density
I=20*10^-3   //A/m^2
//design life of 15 years
t=15*365*24*3600  //sec
//charge= 2 faradya
Q=2*96490  //C
//charge needed per m^2 of structure's for design life
q=I*t  //A s
//the amount of magnesium needed
AMg=MMg*q/Q  //kg/m^2
printf("the amount of magnesiun meeded is %f kg/m?^2",AMg)