t = 0.0
dt = 0.25 # try different values

vel = 0.0
pos = 0.0
force = 50.0
mass = 50.0

while (t <= 1):
    vel = vel + (force/mass) * dt;
    pos = pos + vel * dt;
    t = t + dt;
    print "Time: %4.1f     Pos: %5.2f     Vel: %5.2f" % (t, pos, vel)