Answer:
8.0 seconds
Step-by-step explanation:
Remember: at the highest point, the ball's velocity is 0.
Given:
Δy = 80 m
v = 0 m/s
a = -9.8 m/s²
Find: t
Δy = vt − ½ at²
(80 m) = (0 m/s) t − ½ (-9.8 m/s²) t²
t = 4.0 s
It takes 4.0 seconds for the ball to reach the highest point. So the ball spends a total of 8.0 seconds in the air.