"""
Ex 5.9 from "A primer on..."
Simple plot of a mathematical formula,
with labels on the axes.
"""


import numpy as np
import matplotlib.pyplot as plt

v0 = 10
g = 9.81

t_stop = 2 * v0 / g

t = np.linspace(0, t_stop, 101)
y = v0 * t - 0.5 * g * t**2

plt.plot(t, y)
plt.xlabel('time (s)')
plt.ylabel('height (m)')

plt.show()