PROGRAM CAL
WRITE (6 , * ) ' Enter Roughness Ratio (e/d) '
READ (5 , * ) ED
WRITE (6 , * ) ' Enter Reynolds Number (Re) '
READ (5, * ) Re
 6 F= 0.25/(0.434*ALOG( ED/3.7 + 5.74/RE**0.9)**2 )
F= 1/SQRT (F)
ITER= 0
ITER= ITER + 1
G= ED/3.7 + 2.51*F/RE
RF= F + 0.869/G*2.51/RE
DFR= -RF/DFR
F= F + DF
IF (ABS(DF).GT.1.E-6) GO TO 6
F=1./(F**2)
WRITE (6, * ) ' THE FRICTION FACTOR IS ', F
STOP
END