#exer 5.10

from numpy import *
from matplotlib.pyplot import *
import sys

g = 9.81

v_list = sys.argv[1:]

#better version, convert to float directly
#v_list = [float(v) for v in sys.argv[1:]]

for v0 in v_list:
    v0 = float(v0)
    t = linspace(0,2*v0/g,100)
    y = v0*t-0.5*g*t**2
    plot(t,y,label = 'v0 = %g' %(v0))

xlabel("time (s)")
ylabel("height (m)")
legend()
show()

"""
Terminal> python plot_ball2.py 3 5 6
(output is a plot)
"""