PROGRAM PRO2P2 C... C... EULER INTEGRATION OF EQUATION (1.7) USING EQUATION (2.2) C... C... OPEN INPUT/OUTPUT FILES OPEN(1,FILE='INPUT') OPEN(2,FILE='OUTPUT') C... C... (1) INITIALIZATION C... C... INDEX I I=0 C... C... TIME T=0. C... C... INITIAL HEIGHT H0=100. H=H0 C... C... INTEGRATION INTERVAL DT=50. C... C... TOTAL NUMBER OF INTERVALS ITOTAL=20 C... C... MODEL PARAMETERS AC=5000. Q0=10000. CV=500. A= Q0/AC B=-CV/AC C... C... INITIAL DERIVATIVE DHDT=(A+B*SQRT(H)) C... C... (2) PRINT THE SOLUTION C... 1 WRITE(2,10)T,H,DHDT 10 FORMAT(20X,F10.0,F10.1,F10.3) C... C... (3) TAKE A STEP ALONG THE SOLUTION USING EQUATION (2.2) C... H=H+DHDT*DT T=T+DT I=I+1 C... C... (4) EVALUATE THE ODE DERIVATIVE C... DHDT=(A+B*SQRT(H)) C... C... (5) CHECK IF I = ITOTAL C... IF(I.LE.ITOTAL)THEN GO TO 1 ELSE C... C... PRINT THE FINAL (STEADY STATE) VALUE OF H HS=(A/B)**2 WRITE(2,11)HS 11 FORMAT(//,25X,'FINAL VALUE OF H = ',F6.1) WRITE(3,11)HS END IF STOP END