A ball is thrown into the air with an initial velocity of 40 ft/s vertically upwards. t seconds after it has been thrown up, the height of the ball is given by the function `f(t) = 40t - 16t^2` .
The average velocity of the ball for a time period between `t_0` and `t_1` is given by:
v = `(f(t_1) - f(t_0))/(t_1 - t_0)`
(The entire section contains 150 words.)