Zero velocity A projectile is fired vertically upward and has a position given
by \(s(t)=-16 t^{2}+128 t+192,\) for \(0 \leq t \leq 9\)
a. Graph the position function, for \(0 \leq t \leq 9\)
b. From the graph of the position function, identify the time at which the
projectile has an instantaneous velocity of zero; call this time \(t=a\)
c. Confirm your answer to part (b) by making a table of average velocities to
approximate the instantaneous velocity at \(t=a\)
d. For what values of \(t\) on the interval [0,9] is the instantaneous velocity
positive (the projectile moves upward)?
e. For what values of \(t\) on the interval [0,9] is the instantaneous velocity
negative (the projectile moves downward)?