x# = 150.0 :` starting position
m# = 10.0 :` mass
R# = 150 :` resting length
K# = 0.6 :` spring coefficient
v# = 0.0 :` velocity
f# = 0.9 :` friction
backdrop on
color backdrop 0
sync on
sync rate 60
dim points(12,1)
 
repeat
 
 
if mousex() > x#-10 and mousex() < x#+10 and flag = 0 and mouseclick()
mx# = mousex() - x#
flag = 1
endif
if flag = 1 and mouseclick()
x# = mousex() - mx#
else
flag = 0
force# = -k# * (x#-R#)
v# = (v# + force#/m#)*f#
x# = x# + v#
endif
 
 
ink rgb(120,120,0),0
box R#-10,230,R#+10,250
ink rgb(255,255,255),0
box x#-10,230,x#+10,250
 
rem draw spring
h# = (R#/x#)*20
if h# > 20 then h# = 20
offset = x#/12
for t = 1 to 12
if t mod 2 = 0
y = h#
else
y = -h#
endif
points(t,0) = offset*t
points(t,1) = 240+y
next t
line 0,240,points(1,0),points(1,1)
for i = 1 to 12
j = i+1
if i = 12
line points(i,0),points(i,1),x#,240
else
line points(i,0),points(i,1),points(j,0),points(j,1)
endif
next i
rem end draw spring
 
 
 
set cursor 0,0
print "force: ",force#
print "pos: ",x#
sync
until spacekey()
end