10  COM N5
20  GOTO 70
30  CHAIN "$FORCE1"
40  CHAIN "$FORCE2"
50  REM PROGRAM NAME = FORCE, DYNAMICS
60  REM CHAINED TO FORCE1, FORCE2
70  PRINT "DO YOU WANT INSTRUCTIONS FOR RUNNING FORCE?  ";
80  DIM W$[10]
90  K2=240
100  ENTER K2,K3,W$
110  PRINT '10;
120  IF K3<0 THEN 70
130  IF W$="YES" THEN 160
140  IF W$#"NO" THEN 70
150  GOTO 310
160  PRINT 
170  PRINT "FORCE DEMONSTRATES THE EFFECT OF AN UNIFORM FORCE"
180  PRINT "ON THE MOTION OF A MASS.  THE MOTION IS SIMULATED BY PLOTTING"
190  PRINT "SUCCESSIVE POSITIONS OF THE MASS."
200  PRINT "THERE ARE THREE PARTS, AND THEY SHOULD BE RUN IN THE FOLLOWING ORDER:"
210  PRINT 
220  PRINT "   1. APPLYING AN UNIFORM FORCE TO STOP A MASS WHICH IS MOVING"
230  PRINT "      UNIFORMLY ALONG A STRAIGHT LINE."
240  PRINT 
250  PRINT "   2. APPLYING A FORCE PERPENDICULAR TO THE DIRECTION OF MOTION"
260  PRINT "      OF A MASS."
270  PRINT 
280  PRINT "   3. APPLYING A FORCE AT AN ANGLE BETWEEN 0 AND 90 DEGREES"
290  PRINT "      TO THE DIRECTION OF MOTION OF A MASS."
300  PRINT 
310  PRINT "WHICH PART DO YOU WANT (1, 2, OR 3)?  ";
320  ENTER K2,K3,P
330  PRINT 
340  IF K3<0 THEN 310
350  N5=P
360  IF P=1 THEN 30
370  IF P=2 OR P=3 THEN 40
380  GOTO 310
390  END 
