from math import *

window_coordinates(-100,-100,100,100)
create_line(0,-100,0,100,'red')
create_line(-100,0,100,0,'red')
a = -100.0/30.0
m = 50
v = 0
t = 0
dt = 0.1
i = 0
p = 0
x = 50
vx = 0
y = 0
vy = 10
ax = 0
ay = 0
flag = True

while (x!=50 or flag):
  t+=dt
  xa = x
  va = v
  ax = a*(x/sqrt(x**2+y**2))
  ay = a*(y/sqrt(x**2+y**2))
  vx += ax*dt
  vy += ay*dt
  y+=vy*dt
  x+=vx*dt
  p = create_filled_circle(x,y,1.5,'black','cyan')
  #erase(p)
  flag = False