10  REM PROGRAM NAME = CENTR2, FORCE TO MASS IN MOTION
20  REM CHAINED TO CENTRI, CENTRQ, CENTR3
30  GOTO 50
40  CHAIN "$CENTRQ"
50  DIM A$[20],B$[3]
60  DIM X$[50]
70  X$="123456789"
80  X=0
90  PRINT '10"----- SECTION 2:"'10
100  PRINT "HERE IS A SIMULATED PHOTOGRAPH OF A MASS IN UNIFORM MOTION TO THE EAST:"
110  PRINT 
120  PRINT "     *      *      *      *     *"
130  PRINT 
140  PRINT "OBSERVE ITS MOTION "'7"W"'7"H"'7"ILE YOU APPLY A UNIFORM FORCE TO IT."
150  X=X+1
160  PRINT 
170  PRINT "--PART "X$[X,X]":  WHICH DIRECTION FOR THE FORCE: EAST,SOUTH,OR WEST?  ";
180  ENTER 200,W,A$
190  PRINT 
200  PRINT '10"----SIMULATED PHOTOGRAPH:"'10
210  IF A$#"EAST" THEN 240
220  A=1
230  GOTO 380
240  IF A$#"SOUTH" THEN 270
250  A=2
260  GOTO 380
270  IF A$#"WEST" THEN 300
280  A=3
290  GOTO 380
300  IF A$#"NORTH" THEN 920
310  A=4
320  PRINT "     IMMPOSSIBLE ON THIS TELETYPE."
330  GOTO 170
340  PRINT "     RIGHT!"
350  RETURN 
360  PRINT "     WRONG. EXAMINE THE SIMULATED PHOTOGRAPH AND TRY AGAIN."
370  RETURN 
380  GOSUB A OF 820,850,880,910
390  PRINT 
400  PRINT "THE DIRECTION OF THE FORCE IS "A$"."
410  PRINT "IN WHICH DIRECTION IS THE RESULTING VELOCITY?  ";
420  B=1
430  GOTO 510
440  IF A=2 THEN 640
450  IF C$#"EAST" THEN 480
460  GOSUB 340
470  GOTO 490
480  GOSUB 360
490  PRINT "IN WHICH DIRECTION IS THE ACCELERATION?  ";
500  B=0
510  DIM C$[10]
520  ENTER 200,W,C$
530  PRINT 
540  IF B#1 THEN 570
550  IF A=1 THEN 570
560  GOTO 440
570  IF A=2 THEN 640
580  IF C$=A$ THEN 610
590  GOSUB 360
600  GOTO 410
610  GOSUB 340
620  IF B=1 THEN 490
630  GOTO 750
640  IF B=1 THEN 700
650  IF C$="SOUTH" THEN 680
660  GOSUB 360
670  GOTO 490
680  GOSUB 340
690  GOTO 750
700  IF C$="SOUTHEAST" THEN 730
710  PRINT '10"     WRONG. IS IT EAST, SOUTH, OR SOUTHEAST"TAB(45);
720  GOTO 520
730  GOSUB 340
740  GOTO 490
750  PRINT 
760  PRINT "WANT TO TRY ANOTHER FORCE?  ";
770  ENTER 200,W,B$
780  PRINT 
790  IF B$="YES" THEN 150
800  IF B$="NO" THEN 40
810  GOTO 760
820  PRINT 
830  PRINT "     *       *         *          *             *"
840  RETURN 
850  PRINT 
860  PRINT "     *      "'10"*      "'10'10'10"*      "'10'10'10'10'10"*     "'10'10'10'10'10'10'10"*"
870  RETURN 
880  PRINT 
890  PRINT "     *     *   * *"
900  RETURN 
910  END 
920  IF A$="NORTHEAST" THEN 970
930  IF A$="NORTHWEST" THEN 970
940  IF A$="SOUTHEAST" THEN 970
950  IF A$="SOUTHWEST" THEN 970
960  GOTO 170
970  PRINT "   NOT PROGRAMMED FOR THAT DIRECTION."
980  GOTO 170
990  END 
