Answer
0.88s; 0.95m
Work Step by Step
Let x= 0 and y = 0 where the jumper starts, and let upward be the positive y direction. The vertical acceleration is $-9.8 \frac{m}{s^{2}}$, negative because it is directed downward.
The time of flight is found from the constant horizontal velocity.
t = 8.0 m/(9.1 m/s) = 0.88 s
The time to fall from the highest height is half of that, or 0.44 s. Use equation 2.11b, with a starting vertical velocity of zero, to find a height of 0.95 m.